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What Caused my Tomato Plant to Wilt, Part 2

13 August, 2019 by amygwh

One of my two mature, productive tomato plants wilted last week. Surprise! My previous article (was it just five weeks ago?) about wilting tomato plants was more timely than I knew.

This is the story of what happened.

Wilted, green top of tomato plant — The whole plant had wilted. See the droopy leaves up top?

We had rain. The rain in our area has been patchy, so the rain in my yard may not be like the rain in your yard, but one day we had about 10 hours of steady rain. When I looked out the front windows the next morning, thinking that the garden would probably look great after all that water, I saw that one of my tomato plants had wilted.

I thought back to my previous article about the steps to follow, to figure out what happened to my plant.

At the very least, I can say with confidence that dry soil was not the cause of the wilting.

The plant hadn’t wilted only on one side, and it wasn’t merely slightly droopy. All the leaves on the entire plant were hanging limp on the branches, and smaller branches were sagging.

Tomato stems suspended in jar of clear water. — The streaming test for bacterial wilt was negative.

At first, I thought “cool, bacterial wilt”, since the wilting was so sudden.

Checking for Bacterial Wilt

This is a disease I have seen only once, but I knew that one sign of bacterial wilt was sudden wilting of the entire plant.

Often, this wilting takes place in hot weather and moist soil.

I trimmed off leaves and branches to do the bacterial wilt streaming test. If bacterial wilt was the cause, then white cloudy ooze should stream out of the branches when they were suspended in water.

When the first couple of leafy branches failed to produce the white cloudy streaming that I expected, I cut a thicker section of stem to add to my jar of clear water, to see if maybe I just hadn’t used a big enough section of branch. Ten minutes later, the water was still clear.

Looking at base of the plant for more clues

Then, I finally looked at the base of the plant, where the stem emerges from the ground. This was when I thought “uh oh”. There was white fungus-looking stuff right near the base of the plant and climbing up the stem.

White stuff on ground and on two green stems growing through the white stuff

To be honest, this is probably a bigger problem than bacterial wilt would have been for the future of my garden. My knowledge of white fungus climbing up stems from the ground leads me to think the fungus is Southern Blight. (Link is to a pdf about Southern Blight from University of Kentucky)

White fungus climbing up green tomato stem and extending into nearby soil

Lots of fungal diseases are host-specific. That means that they can infect only a limited number of crops. Southern Blight, on the other hand, can infect many kinds of crops.

How can I reduce future damage from Southern Blight?

I already removed the plant, including as much of the root system as I could. University of Kentucky’s information (linked previously) recommends removing the soil in that area, too, to reduce the number of reproductive bits, called Sclerotia, in the garden.

The next recommendation that organic home gardeners can follow is to grow plants that can resist Southern Blight in that area for a few years.

Resistant plants, according to University of Florida and Louisiana State University include woody plants, ornamental grasses, corn, and wheat.

The other recommendation is to raise the soil pH a bit. The fungus grows more slowly in higher-pH soils.

The good news: no evidence of root-knot nematodes

Smooth roots from dug-up tomato plant — Smooth, tapering roots show no evidence of root-knot nematodes.

If there were root-knot nematodes adding to the damage, the roots would look lumpy. Maybe other gardeners are not as relieved as I am to see this lack of lumpiness, but some years my garden is seriously affected by the nematodes.

Where did the Southern Blight come from?

This is hard to know. My garden has never, until now, shown any sign of harboring Southern Blight. The disease can travel on infected plants, mulches, soil, and contaminated tools. I am thinking that it could also be spread by ground-scratching birds, but they are not mentioned in any of the publications I checked.

A new tomato plant growing nearby

At the end of June, when we returned from five weeks of travel and before we drove across Texas to visit family in the Austin and Houston areas, I planted two tomato seeds in the garden. Luckily, they are in a separate garden bed from the blighted plant.

I set the seeds inside a collar formed by a paper cup that had the bottom removed. The collar was to help hold moisture and to protect the seeds from being eaten. I watered the area well before we got in the car and headed west.

Small tomato plant next to a stake, and several Swiss chard plants planted in an arc nearby — Healthy, young tomato plant was started from seed in late June.

Amazingly, when we got back from our 8-day tour of relatives, a little tomato plant was standing where I had planted those two seeds.

I had planted some Swiss chard and a leaf-amaranth in the same little garden area, and they were coming up, too. A caterpillar of some kind found those to be delicious, so I had to replant the greens, but all is looking good now.

That little tomato plant has flowers on it today. If all goes well, there will be more garden-tomatoes coming into my kitchen by late September, and, hopefully, the potential disaster of Southern Blight will not be causing too many more problems.

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Growing Turmeric, and Other Garden Adventures

5 August, 2019 by amygwh

An abiding desire to grow more good food is evident at The Metro Atlanta Urban Farm (MAUF). Some of that evidence is in experiments and unconventional practices seen throughout the farm. One recent experiment at the urban farm is turmeric.

Man in jeans, a red and blue plaid shirt, and red and blue striped hat, pulls aside large green leaves of turmeric plant to show the white flower spike coming up behind the leaves. — Mr. Moses Cobb, with some of his turmeric plants.

When I visited the farm and its community garden last week, one volunteer, Mr. Moses (Robert) Cobb, showed me around the farm, which includes ginger and turmeric plants. These plants are his own project, and they are beautiful.

He told me that the project originally was to grow ginger. He had bought some rhizomes, the thick root-like part that we use in the kitchen, at a grocery store to grow, but they never did grow for him. He suspected that they had been treated with something to prevent sprouting.

He finally was able to get some fresh, untreated ginger rhizomes. A friend had located and mailed them to him, and the packet, when it arrived, included turmeric rhizomes.

If you want to grow turmeric and ginger

Moses noted that ginger is a slow grower for him. Right now, it is protected in a glass-house. The ginger is growing in several pots. The plants look healthy, but the rhizomes do not appear to be spreading robustly across their containers.

The turmeric, however, is growing very well. Moses started the rhizomes together in one container, but he has separated and divided and had to rustle up additional large-size containers to transplant them into.

Ginger plants, with large leaves on tall stems, growing in a greenhouse. — Healthy ginger plants, but less lush than the turmeric.

Healthy ginger plants, but less lush than the turmeric.

Moses has found that the turmeric does best when grown in partial shade. Too much sun results in burnt leaves.

Time-to-harvest for ginger and turmeric

An article out of North Carolina State University (NCSU) about growing turmeric and ginger tells that both of these crops can produce new rhizomes in the eight months of growing time that many gardeners in the Southeastern US have.

The article points out that neither of these plants will survive a freeze. In addition, the growing season is too short, across much of the Southeastern US, for the turmeric to form the thick skin that helps it “keep” through the winter.

Turmeric plants need a full twelve months for their rhizomes to develop that thicker skin. NCSU suggests planting in containers that can be moved indoors or into a greenhouse, to produce the more mature rhizomes if those are your goal.

Starting ginger and turmeric plants from rhizomes

This is NCSU’s information on sprouting rhizomes for both ginger and turmeric:

To initiate sprouts, place a 1.5” piece of rhizome in potting media with ample moisture in a warm, humid location (72-80 degrees F) for 4-6 weeks. A tray with a plastic dome or some kind of enclosed container is ideal to keep in moisture, but light is not necessary until the sprouts start growing. You can sprout either mature, shelf-stable rhizomes, or baby rhizomes may also produce sprouts. Once they have sprouted, gradually harden them off before planting. Take the plants outside an hour or two per day, gradually increasing that time, for approximately two weeks before transplanting outside.
Read more at: https://caldwell.ces.ncsu.edu/2018/10/ginger-and-turmeric-tropical-superfoods-for-the-garden/

Where to get good rhizomes

Rhizomes are the root-like part that we use in the kitchen for both of these plants. The rhizomes are also what we plant in the soil for growing new plants. Many of the rhizomes in grocery stores, as Moses found, won’t sprout.

Not all of us have a friend who can send us fresh, untreated rhizomes, but some seed companies sell them. Southern Exposure Seed Exchange, in Virginia, sells turmeric rhizomes and ginger and turmeric plants. Fedco Seeds, up in Maine, also sells ginger and turmeric pieces for sprouting.

Neither of these sources sells the rhizomes year-round, and shipping is limited to March/April. Plan to order early if you want to grow these, because it looks like supplies may be limited.

Why grow turmeric at home?

The glossy green leaves and spectacular flowers are reason-enough to try growing this plant at home. The plant is beautiful! Some of us, though, also use a little turmeric in our cooking. For veggie gardeners who like to “grow their own” as much as possible, adding this spice to the landscape is a big win.

Also, although I do not typically spend much time looking into specific health benefits of each and every veg, herb, spice, and fruit that I grow, some gardeners do. My gardening friends who pay more attention to chemical properties of plants probably already have found loads of research about the health-boosting benefits of turmeric.

Elsewhere on The Metro Atlanta Urban Farm

Two pink zinnia flowers and one butterfly, a silver spotted skipper — MAUF also grows flowers that attract pollinators.

Like in gardens all across the Southeastern US, weeds are gaining ground in spots, and some crops are starting to look a little ragged. Tomato plants in particular are beginning to slow down. Tomato plants growing in the high tunnels, though, that are protected from rainfall, had healthier looking leaves than plants that are exposed to rain.

Many of the melons are growing on hugelkultur mounds. The farm is producing a LOT of watermelons this year, and they all look good. Hugelkultur beds, which are built on and around piles of woody debris, maintain an even moisture level, which is a big boost for many crops. (How to build your own hugelkutur bed is described in this Permaculture News article.)

The melon areas have a lot of weeds growing in them, but this seemed to be helpful in one particular way. When I volunteered at a farm here in Cobb County, any melons that touched the bare ground ended up with a “belly rot”. We had to find the developing fruit and place a protective barrier (styrofoam tray, plastic sheeting) under each one to prevent this rot from invading the melons.

At MAUF this week, I didn’t see any belly rot on the melons. This could be because the thick weeds formed a barrier that held the melons away from the soil. The potential for rot-prevention may be a good reason to leave some weeds, strategically, around the garden.

Equipment maintenance and repair is an ongoing project for most small farms.

Another experiment on the farm, in one of the high tunnels, was growing strawberries in long fabric tubes. The fabric tubes had been filled with growing medium (soil). The plants were planted in slits made on the top side of the tube. The plants looked good, so this probably counts as a successful experiment.

When I asked Moses about the baby plants growing on the long runners that the original strawberry plants were sending out, he said that in a few weeks, as the little plants developed more of their own roots, he would be planting those.

The Metro Atlanta Urban Farm

The farm (MAUF) includes a community garden, and it also assists other community gardens and school gardens in Atlanta. I visited the farm because Baker Creek Heirloom Seeds had sent me a box full of lovely seeds.

I had already shared some of the seeds at a meeting of Cobb Community Gardens, a group of garden coordinators and other garden leaders. Participants at that meeting all took some seeds back to their community gardens, but there were still seed packets left. To get more of the seeds into the hands of gardeners who could use them, I contacted Bobby Wilson, co-founder of MAUF.

MAUF’s work with so many area gardens means the seeds will get distributed to even more gardeners.

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Southern Peas for the Summer Garden

30 July, 2019 by amygwh

Southern peas include crowder peas, field peas and cowpeas, but the type that may be most familiar is black-eye peas. These are all classic Southern crops that produce well in hot weather. Even better, they tolerate a lack of rain pretty well.

Mounded growth of Southern peas in a front yard garden. — ‘Purple hull speckled’ cowpeas are a lower-growing variety, suitable for small gardens.

Southern peas that I have tried include black-eye peas, common field peas, javy peas, purple hull peas, lady creams, Colossus peas, and Piggott family cowpeas. All the varieties that I have cooked and eaten have a flavor similar to black-eye peas, but not exactly the same.

Anyone who has grown several varieties of tomatoes will understand how that works. They all taste like tomatoes, but there are differences, too. The differences are what makes growing more than one kind worthwhile!

For gardeners who may not be familiar with Southern peas, these are not an edible-pod type of bean. We eat the shelled-out peas from inside the pods.

This year, my Southern pea patch is all ‘Purple hull speckled’ cowpeas.

Look for a fast-maturing variety

Southern peas can be a good crop to plant in mid-summer, if the space won’t be needed for other crops before mid-October. Many varieties produce mature peas in about 60 days.

Purple pea pods and brown shelled-out Southern peas in a flat basket — Mature pods of ‘Purple hull speckled’ and their brown, dried peas.

Gardeners who plant a fast-maturing variety of Southern peas within the next week or two are likely to begin harvesting peas in early October. Any gardener as far South as the metro-Atlanta area, planting now, can expect to harvest plenty of peas before the first frost.

‘Purple hull speckled‘ has peas ready for picking in about 60-62 days (two months). I noticed that Baker Creek also offers a variety called ‘Six week purple hull’ that sounds promising as a fast-maturing type.

Plant size when full grown

Those of us with small gardens, especially when the gardens are in the front yard, like mine, try to be aware of smaller-growing varieties, even when we totally plan to grow huge ones. The classic ‘Purple hull pinkeye’ is a neatly mounded plant, growing to about two feet high. ‘Colossus’ peas that we grew at the farm where I used to volunteer have a similar growth habit.

Some Southern peas, however, are long vining plants that will sprawl over the whole yard if they are not trellised. ‘Piggott family’ is one of the vigorous growers. Years ago (2012!), I made a little video about these peas:

‘Purple hull speckled’, the variety I am growing this year, is described in more than one seed catalog, as being a short, bush plant, but that is not exactly how they turned out in my garden. The plants in my garden do have a basic mound shape at the core, but they have sent out runners, long runners.

Mounded patch of Southern peas in the garden. — ‘Purple hull speckled’ pea patch showing mature pods and emerging vines.

If I had known what was coming, I would have set up something for them to climb. Instead of going up, the plants are reaching into the lawn and across other plants in the garden.

Productivity

In the video about ‘Piggott family’ peas linked above, I tell that the small patch of peas has already produced two quarts of dry peas, and it is easy to see that more are on the way. The plants are covered up in pea pods!

Unfolding purple pea flower and a newly-formed pea, together on one stem. — After the first flush of abundant Southern pea pods, ‘Purple hull speckled’ is making more peas.

This year’s smaller patch, planted in a two-by-three foot space, has produced about one quart of dried peas so far. The plants also still have plenty of flowers and smaller pods that will, eventually, add to the total harvest.

For this variety, there was a big flush of peas to start, but the plants continue to make flowers and pods, the way some bush-type green beans do — a big harvest at first, then smaller amounts until the plants are decimated by pests or killed by frost.

When to harvest

The great feature of purple hull types is the color change, from green pods to purple pods, that tells a gardener when to harvest the peas. I love a color-coded garden!

Shelled-out peas, some green and some brown — Shelled-out peas shrink and develop their distinctive coloration as they dry.

For plants that do not have the purple hull feature, like ‘Piggott family’, I harvest by feel. If the pods feel as though they are beginning to dry, when the pods are turning a bit papery and tan, then they are ready.

Usually, leaving the pods on the plants until they are bone-dry is totally safe. However, in wet weather, pods many need to be harvested a little early, so they won’t turn moldy on the vines.

Most Southern peas are easy to harvest because of the way the pods are held away from the plants on stiff stems. The gardener does not have to hunt through the leaves to find the pods!

Wildlife

I have read that deer love Southern peas. I’ve also read that deer leave Southern peas untouched. So far, deer have not eaten my plants, but that could be a result of luck more than how much deer like to eat Southern pea plants.

Other wildlife most commonly attracted to Southern peas are wasps. For some people, this may be a problem, but I have never been stung while working around Southern peas.

Many insects are attracted to Southern peas because of the nectaries that are on the stems near the flowers. Nectar is a main food for adults of some of the predatory wasps. These wasps hunt caterpillars to feed to their babies, so attracting these wasps to your garden is actually a good thing.

Honeybees visit the nectaries of Southern peas
Orange wasp at a nectary on my Southern peas
Another predator in the Southern peas
Ants. Is anyone surprised?

Insect pests

North Carolina State University’s publication about Southern peas notes that the cowpea curculio is a serious pest on Southern peas, but not the only pest. More common garden pests like aphids and stinkbugs can also cause damage in the Southern pea patch.

So far, though, my Southern peas, over many years of growing them, have been untroubled by pests.

How to grow Southern peas

Soil fertility

Southern peas are known as “light feeders”. This means that they do not need a heavy dose of fertilizer to grow well and make lots of peas. If the space you are planning to grow them was already well-fertilized for the crop that was there before them, adding a layer of compost (2-3 inches deep) may be all you need.

The downside of a “light feeder” is that some soils may be so rich in nutrients that the plants grow to be lush and beautiful without producing many peas.

This crop is also one that does well in a lower pH soil. A range of 5.8-6.3 pH , according to Clemson University extension, is best — this is more acidic than the preferred pH range for some garden vegetable crops.

purple flower of Southern peas — Southern pea plants won’t make flowers or peas if too much fertilizer is used

My garden is in the red Georgia clay, and its pH is about 6.5, which is close enough. I typically amend it with compost and other organic sources of nutrients. For my garden, adding more compost before planting Southern peas in mid-summer is all that is required.

Deep, raised beds, filled with commercial composts that include some animal wastes, might not be good places to grow Southern peas. These composts can be too high in nutrients for good pod production.

Planting

Even in spring, I plant my Southern peas directly in the garden. I don’t start them indoors in pots/flats/trays. As a heat-loving crop, Southern peas are going to perform their best when planted in warm soil. I planted this year’s ‘Purple hull speckled’ peas in the second week in May.

Seed spacing

The plant spacing recommendations I have found are for row crops. If your garden is all row-crops, you can use the 3-4 inch spacing for smaller varieties and 6-8 inches for larger varieties, with 24-36 inches between rows.

If, however, you plant in blocks, using like I often do, some experimenting with plant spacing may be required. My little patch is ringed by some foldable wire fencing, that encloses a space about two-by-three feet. It contains 12 plants. The spacing is about 6 inches, but none of the plants is up close to the wire enclosure.

I had to lean down and hunt through the leaves to count them and estimate the spacing, because I forgot to write it down at planting time.

Seed depth

Plant the seeds about an inch deep. Then, water them in well.

In general, the plants will do fine most of the summer without regular watering, but the seedlings, the newly emerging plants, will need regular water for a few weeks.

Southern peas in the kitchen

Black-eye peas may be the most familiar Southern pea for most people. These are the peas my Mom says (and other people seem to agree) we need to eat on New Year’s day, for good luck in the coming year.

Even if you love them, though, branching out to other types is worth the effort.

Field peas and crowder peas all (I think) cook up to make a brown gravy that is delicious. A good way to start eating these peas is as gravy to pour over mashed potatoes. The ‘Piggott family’ variety, especially, is great to use this way.

Cream peas seem to be the mildest flavored types. The peas usually are smaller, too, than the other types of Southern peas.

There is a Southern pea grown in a small part of Italy, the Lake Trasimeno bean, that has been included in the Slow Food Ark of Taste. I have been lucky in being able to try these beans in Italy, and each time they were served the same way: cooked, then drained, then drenched in olive oil, with a little salt added.

The tiny size and mild flavor of the Lake Trasimeno beans made me think that cream peas might be their closest match in the United States. Last year, I purchased a bag of Lady Cream peas to prepare the same way, and the flavor is close enough that I will make it again. The peas I purchased are not organic, which is a good reason to grow my own in future gardens.

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Duct Tape for Pest Control

20 July, 2019 by amygwh

At the Plant-a-Row-for-the-Hungry garden where I volunteer, squash bug eggs have shown up on some of the squash plants. The eggs stick very tightly to the leaves, making them difficult to remove by hand. Duct tape, though, can help with egg removal.

Why are squash bugs “bad”?

Squash bugs aren’t essentially bad, but their activity on our plants can have a bad result. North Carolina State University’s Extension tells us that squash bugs suck the sap out of our squash plants.

Even if the plants don’t die directly as a result of this feeding activity, it can weaken them. The result is that they can make fewer squashes and become wilted. Neither of those outcomes is good. Getting rid of the eggs can slow the infestation down.

How to use tape to remove squash bug eggs from leaves

Cluster of tiny, shiny, bronze colored eggs on a green leaf. — Cluster of shiny, bronze colored squash bug eggs on a squash leaf.

First, identify the clusters of eggs.

What the eggs look like

Squash bug eggs are pretty distinctive. They are shiny, hard, bronze-colored, and appear in clusters on the leaves of squash plants. Sometimes, they are on the stems, too, but this is less common.

Why remove the eggs, rather than smash them where they are? These particular insect eggs are difficult to smash without damaging the leaves. Removing the eggs completely from the plant is the best hope for keeping the numbers of hatching eggs to a minimum.

Duct tape egg removal technique

Actually, the blue painters tape works, too, if you don’t have duct tape. It is likely that clear package-sealing tape would also work, but I haven’t tried it.

Bronze-colored bug eggs and hairy yellow larvae stuck to the sticky side of a piece of duct tape. — Duct tape can lift eggs and squishy larvae from leaves of your garden crops.

Just press the sticky side of a short section of tape to the squash bug eggs, then peel it away from the leaf. Most of the eggs will be stuck to the tape.

You may need to press a fresh section of the tape to the eggs a second time to get them all, but the tape works. With little effort on your part, the eggs will be gone from the leaves.

Now, of course, those shiny eggs are on the tape. When your piece of tape is “full”, fold it over and smash the eggs as well as you can, before putting the tape into a trash bin.

Duct tape can lift away other pests, too

You may have noticed that there are some yellow fuzzy things on the tape pictured above, along with the squash bug eggs. Those fuzzy things are the larvae (babies) of squash beetles.

Normally, I just smash those beetle larvae with my fingers, but I already had the tape in hand. Picking the larvae up with the tape was convenient, easy, and less icky than my usual method.

You can read about squash beetles and the damage they can inflict on your squash patch in my 2018 article about those particular pests. Older articles, from 2015 and 2012 confirm that this is not a new pest for my area.

Upbeat pictures, to end a “pest post”

After thinking about pests for awhile, it is good to switch over to thinking about more of the positive parts of gardening and being out of doors. These pictures might help:

Yellow swallowtail butterfly on large squash flower, that also has several bees working at the center.
Home garden vegetables from a recent morning’s harvest.
Frog on the table on our back deck.

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The Mid-July Garden

14 July, 2019 by amygwh

From gardens across the area, I’ve had reports of great successes and annoying troubles. Gardeners are bringing amazing vegetables into their kitchens from some of their crops, but the usual troubles of mid-summer are beginning to appear.

First — here are some successes:

A recent morning’s harvest
‘Park’s Whopper’
‘Blue marbut’ pole bean flowers
‘Oda purple bell’ peppers
My Southern pea patch
‘Mrihani’ basil, a new variety for me

Now for some less-than-successes, which we all experience to some degree pretty much every year:

Insect pests

In the past week, I’ve seen for myself or heard other gardeners discuss these garden pests:

green tomato with hole near stem — Hole in tomato near the stem is a sign of fruitworm activity

Fruit worms on tomatoes and peppers (in my own garden)
Pickleworms on squash, melons, and cucumbers
Squash vine borers on yellow squashes and zucchini

Plant disease

More than one gardener has mentioned that all their tomato plants, except for one, look healthy. The one exception has been a plant that wilts in the day, then seems to recover at night.

Going through the steps to identify the cause, listed in my “wilting tomato plants” article, can help. Checking soil moisture and looking for stem damage are easy steps that anyone can do. The hard steps are the ones that ask the gardener to sacrifice the plant.

I understand. We love plants. Pulling them up to look at the roots or cutting them down to look inside the stem just seems wrong. However, those are the best ways to identify the problems that begin underground (nematodes and wilt-funguses). Also, leaving ailing plants in the garden can allow some problems to spread to other plants.

Problems caused by factors like the weather

red tomato showing a black soft spot on its underside — Blossom end rot appears on the bottom side of a tomato

Another way to name these problems is to call them “physiological”. They are the plant’s reaction to things like temperature and uneven watering (or too much rain, then no rain, then too much rain, repeat).

Blossom end rot

I see this most often in tomatoes, but Iowa State University’s article on blossom end rot says it also occurs in peppers and squashes. This looks like a dark soft spot that appears at the bottom of the fruit — the side opposite the stem — and Iowa State’s article says it is caused by a lack of calcium, that is caused by uneven watering.

Considering that I was away from home for much of May and June, it may be a miracle that I have seen blossom end rot on only a few of my tomatoes this year. Or, maybe the miracle is in the mulch that I put down before our travels began. Mulch keeps moisture in the soil longer.

Other gardeners have been less lucky; a large number of their tomatoes have this problem.

Sunscald

If there are squishy spots on the shoulders, up near the stem, of your blocky fruits like tomatoes and bell peppers, the cause is likely to be exposure to too much sun. In essence, the fruits get sunburned, but the specialists call it sunscald.

Avoiding sunscald is a good reason to prune tomato and pepper plants as little as necessary. (To see how I prune my tomato plants, watch the video in my article on determinate vs. indeterminate tomatoes.)

Some plants, even without pruning, do not have enough — or large enough — leaves to shade their fruits. This could mean that the plants are not getting enough nutrients to grow well.

Tomatoes not getting ripe

A lack of tomato-ripening is causing frustration among several gardeners I spoke with last week. There are plenty of big, green tomatoes on their plants, but none are turning red, even though they should be.

Depending on which state’s publications you read, in order for the red pigment in tomatoes to form, the daytime temperature has to stay either below 86 degrees F (Ohio State University) or below 90 degrees F (Arizona State University). The difference may be in the tomato varieties tested.

Nighttime temperatures also need to go below 70-to-75 degrees F for the red pigment to form.

Weirdly enough, my tomatoes are ripening on the plants, and they are growing with essentially the same air temperatures as the tomatoes of my gardening friends.

One of my friends is growing one of my ‘Park’s Whopper’ plants, started alongside the one that is in my garden, so we know that the problem isn’t just a difference in tomato varieties. Maybe my plant is in a cooler spot — with a different enough “microclimate” to allow ripening.

If your tomatoes are not ripening, and you are sure that they should be by now, consider rigging a shade cloth over your plants. Shade cloth can reduce the temperature by 5-9 degrees F, which could be all that your tomatoes need.

Tomato plant and yellow flowers — Section of my July garden, with black-eyed Susans to the right.

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What Caused my Tomato Plant to Wilt?

7 July, 2019 by amygwh

Some varieties of tomato die in my yard. The most obvious sign of their impending doom is wilting. The presence of many dead leaves is another easy-to-notice sign.

Wilted green leaves on a tomato plant. — Wilting of tomato leaves can have many causes.

When a tomato plant starts to look extra-pathetic, figuring out the cause is important. Sometimes, the plant can be saved. More often, it can’t, but knowing the cause can help the gardener prevent problems in the next-summer’s garden.

This article describes the way I figure out what is wrong with an ailing tomato plant.

Wilt versus leaf roll

Stressed plants will sometimes roll or curl their leaves. This is different from wilting. In the leaf roll response, leaves roll or curl upward at the edges. The roll can be extreme, so that each rolled leaf is almost cigar-shaped, with the lower leaf surface seen on the outside of the roll.

University of Washington’s publication on leaf roll in tomatoes explains that this sign has several possible causes, that are not diseases, including high temperatures and fluctuating soil moisture levels, and that it is more common in indeterminate plants than in determinate plants.

Wilted leaves, unlike leaves doing the leaf roll thing, do not roll inward/upward.

Wilting caused by something other than disease

Wilting in tomato plants can have non-disease causes.

Soil moisture

The obvious first thing to check when a plant looks wilted is the soil moisture level.

Tomato plant standing in water puddle — Too much water.

It makes sense to pretty much everyone that a plant might wilt in dry soil, but when soil is too wet, that can also cause wilting due to roots that have drowned and no longer work to pull water into the plant.

If you aren’t sure about the soil moisture level, poke a trowel down into the soil not too far from the wilted plant, then pull back on the handle to make an open wedge that your hand will fit into. Reach down into the soil with a bare hand to check for dampness.

Too-dry soil is one cause of wilting that a gardener can fix. Too-wet soil is less easy to fix quickly, and a drowned root system takes a long time to overcome.

Damage to the main stem

If a plant is wilted, another thing to check after soil moisture is whether the main stem is damaged.

tomato stem showing wound — Plant may wilt above a wound on the stem.

If the main stem is very damaged, it is possible that the plant’s water-conducting tubes have been damaged, too, and can not move water well-enough through the plant.

A damaged tomato-stem cannot be fixed. If the damage is near the ground, caused by a mechanical injury (being bumped or scraped), raising up a mound of soil above the damaged area may help.

Tomato plants can make new roots on the main stem,. The mounded up soil can allow new roots to form above the damage. Growing new roots takes time, though. The tomato harvest may be slower to arrive and smaller than for a plant that didn’t have a delay.

Loss of roots due to gophers

Gophers can ruin a garden, plant by plant. They burrow underground and eat plant roots. Most of us will not ever have this problem in our gardens, but gophers were my second stepdad’s garden nemesis.

Gophers usually leave mounded trails through the garden. If a plant simply falls over one day, and you discover that its roots have disappeared, look for the trails.

A plant that has lost its roots to gophers won’t recover.

Wilting caused by diseases in the soil

The next step, if all of the above do not seem to be the cause of wilting in your tomato plant, is to dissect the plant for a closer look.

Cut across the main stem near the ground, and look inside the stem. Is the tissue a healthy greenish-white all the way across, or are there some brown areas inside the stem?

Fungus underground

Cross section of tomato stem showing brown sections inside the stem; evidence of a fungal wilt disease. — Cross section of tomato stem showing the browned areas that are evidence of fungal wilt disease.

The two fungal diseases that cause most of the wilting in tomato plants that I have seen in Georgia are fusarium wilt and verticillium wilt.

To be honest, I usually cannot tell which one has caused the trouble, but both will show browned areas inside the stem that are where the fungus has entered the plant through the roots and clogged up the water-conducting tubes.

These diseases cause more trouble in very wet soils.

I have grown the heirloom tomato variety ‘Mortgage Lifter’ in both wet and dry years. In dry years, the plants are productive and make delicious tomatoes through the whole season. In rainy/wet years, the plants die from one of these fungal wilt diseases by mid-July.

EDIT from 20 Aug 2019 – A new soil-borne fungus that attacks tomato plants has shown up in my garden. See my article “What Caused my Tomato Plant to Wilt, Part 2” to read about Southern Blight in my garden.

Bacterial wilt

Bacterial wilt causes rapid wilting of the whole plant. If your plant has wilted completely, seemingly overnight, this is a cause to suspect.

University of Florida’s information on bacterial wilt describes a simple stem-streaming test that you can do at home, to check for this disease:

Cut a stem from the wilted plant and suspend the cut end in clear water. White, cloudy material oozing out of the cut end into the water is a sign that the plant is infected by bacterial wilt. If nothing oozes out of the stem, then bacterial wilt is not the cause of your tomato plant’s wilting.

I have only been able to confirm bacterial wilt as a cause of tomato wilting once, in someone else’s garden, in my many years of looking at wilted tomato plants. That makes me think that this cause of wilting is not super-common.

Wilting caused by nematodes in the soil

Root-knot nematodes — microscopic wormlike creatures — are another possible cause of wilting in tomato plants. If all of the above-ground parts of the plant check out as being fine, except for the wilting, the next place to look is the root system.

Dig up the roots of the wilted plant, and examine them carefully. Healthy roots are creamy white in color, and they are fairly uniform in diameter, gradually decreasing in width as you follow them to the growing tips.

The roots of tomato plants infested by root-knot nematodes are lumpy, looking a bit like they have swallowed large beads.

The University of Arkansas publication (pdf) about root-knot nematodes includes photos of healthy and infested roots, side by side, for comparison. If your plant’s roots are lumpy, then root-knot nematodes are the likely cause of wilting.

Wilting caused by leaf diseases

All of the above causes of wilt can include some yellowing of the leaves, but not brown spots on the leaves. If a tomato plant has many wilted, yellowing and/or browned leaves, and it also has a lot of spotted leaves, then a leaf spot disease is a likely cause.

Leaf spot diseases can affect most tomato plants as the season progresses. These diseases tend to be worse in wet years than in drier years, but nearly every spring-planted tomato plant in the Southeastern US will show some signs of a leaf disease by the end of September.

Brown spots on tomato leaf are a sign of leaf disease
Too many dead leaves; this plant will not recover.

The brown spots on the leaves are an easy-to-see clue.

Cure for wilted tomato plants

Many of the causes listed above do not have an easy cure. Most of them, though, can be avoided in next-year’s garden with some planning.

If the garden soil is in a place that stays wet much of the time, raising it up a few inches can improve drainage and reduce the risk of the moisture-related wilt problems, like the soil-borne diseases.

Another simple step is to grow disease-resistant and nematode-resistant varieties. Many of these are hybrids, not heirlooms, but some heirloom varieties also survive just fine in my garden. Some will do fine in yours, too; however, finding them may take time.

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June in the Garden

23 June, 2019 by amygwh

This year, because of some planned travel in May and June, I planted my summer crops later than usual. I didn’t want crops to mature to harvest-stage, and go to waste, while no one was at home to bring them into the kitchen.

The good news is that, while I was gone, the garden was fine. A neighbor (thank you, Heather!) did water the garden once, in the middle of that extra-hot, extra-dry stretch of weather in late May. However, mulch on the garden held the moisture well enough that the one watering was enough.

How the tomatoes fared

Me with a quite tall ‘Park’s Whopper’ tomato plant. PHOTO/JoeD

I had clipped off the first flower cluster from each of my two tomato plants, as part of my effort to delay production of ripe fruits. Both plants were small when I left, each of them tied to a stake in the center of their large tomato cages.

Now, the ‘Park’s Whopper’ (a hybrid variety) is taller than I am. Yesterday, we stacked another section of a Texas Tomato Cage on top of the first two, to provide support for the higher parts of the plant.

The entire ‘Park’s Whopper’ plant is gloriously green and healthy, and it holds many, many tomatoes.

The first tomatoes on the ‘Park’s Whopper’
‘Black from Tula’ tomato ripening, but notice the brown leaves.

The other tomato plant is a ‘Black from Tula’. This heirloom plant is not as tall, and some leaves have turned brown. I do not yet know why. Our first ripe tomato for the summer will come from that plant, I am sure, since one is already turning. It will probably be spectacularly delicious.

I think, though, based on the presence of several dead leaves, that the plant will not live to produce tomatoes for as long as the ‘Park’s Whopper’.

How the peppers fared

This year’s garden has three varieties of peppers. Plants of the two kinds of sweet peppers, ‘Feherezon’ and ‘Purple bell’, are all alive and productive. We lost one of the ‘Carlo Putini’ Italian hot pepper plants, but the other (there were two, originally) is healthy and loaded with peppers.

We have eaten some of the sweet peppers, but I am waiting for the ‘Carlo Putini’ peppers to turn red and fully ripe before bringing any in.

Some other crops

Cucumber/squash family plants

The cucumbers and zucchini were just seedlings when we left town in mid-May, but they are large and flowering now. The first fruits from both of those should be ready in the next week.

Bean family plants

The pole beans – ‘Blue Marbut’ – and the Southern peas were also just seedlings when we left town. They are all beginning to flower.

Annual and bi-annual herbs

All the basil plants are large, and some are making flowers. Yesterday, I brought in a lot of ‘Genovese’ and ‘Lettuce leaf’ basil to make the summer’s first batch of pesto. That batch is in an ice-cube tray in the freezer, to save for use in winter.

The parsley is large and healthy, and it will be added to many kinds of salads over the next several weeks. Purslane also has popped up around the garden, and some of that went into salads this weekend.

The borage and nasturtium plants have plenty of leaves, but no flowers yet.

Garlic and onions

Bulblets from a winter onion plant, sprouting leaves and roots.

Usually, the garlic is ready to harvest by now, but for some (unknown) reason most of the plants are still mostly green. Soon, though, it will be time to pull those plants.

The only onions in the garden this spring/summer are Grandpa Bill’s ‘winter onions’ (aka: ‘tree onions’, ‘walking onions’). The tiny bulbs that form in a cluster at the top of the stalk are sending out roots and shoots, to make new onions for the coming year.

To plant next

In the next few days, I will be starting some more summer crops, to go into the garden soon. There will be another tomato plant, this one a ‘Winter Keeper’, and some summer greens.

The greens will be Swiss chard, the varieties ‘Perpetual Spinach‘ and ‘Verde di Taglio’. The two look similar, but I am interested to find out whether they grow about the same and whether they work in the kitchen the same.

Another green is the amaranth variety ‘Chinese multicolor spinach‘. The new, small leaves are supposed to be good in salads, and the older, larger leaves for cooking.

Masses of yellow and orange flowers growing at the left side of the garden are for pollinators. The right side of the garden is green, with vegetable plants that have less conspicuous flowers. — Flowers to the left, veggies to the right — the upper garden bed in June.

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Organic Garden Pest Control

18 June, 2019 by amygwh

As the summer progresses, more and more plant-eating pests will find our gardens. Farmers and horticulture specialists call this build-up of unwanted insects and other creepy-crawlies “pest pressure”, and, in the South, it can become spectacular.

However, organic gardeners everywhere have a wide range of non-chemical strategies available to reduce pest-problems.

Simple pest control strategies for organic gardeners

Remove pests by hand

Cluster of shiny orange squash bug eggss on a leaf of summer squash — Squash bug eggs can be lifted off squash leaves using the sticky side of duct tape.

One of the simplest ways to deal with a whole assortment of plant-eating bugs and beetles is simply picking them off the plants and smashing them (possibly while wearing really good garden gloves) or knocking them into a little tub of soapy water, where they will drown. This strategy works for many kinds of beetles and bugs when the population of pests isn’t too large.

Mowing and weeding

Keeping the surrounding vegetation down helps reduce the number of places pests can hang out.

Water spray

Spraying sturdy plants with a hard stream of water can knock smaller, soft-bodied insects like aphids off a plant. Very small insects can’t always manage to climb back up.

Barriers

Bird netting over strawberry plants — Netting set out over young plants can protect strawberries from birds and chipmunks.

Placing fine mesh netting or a specially manufactured row cover over plants can keep them from being attacked by some kinds of insects. Especially if you want to keep an adult form from laying eggs that hatch into a destructive larva/caterpillar, this is a great strategy. I use netting over cabbage family plants to keep from getting cabbage worms and loopers on my crops.

Netting can also protect plants from birds and small mammals, if it is placed over-and-around the plants before the birds and mammals find your crop I get to eat a lot more of my own garden-strawberries when my plants are defended from chipmunks (my nemesis…) with heavy netting.

Baits

Organic-approved baits are available for some pests, like slugs, snails, and roly-polies (aka: sow bugs, pill bugs). These work, but patience may be required.

Bacillus thuringiensis (Bt)

This bacterial product is toxic to certain insects and is certified for use in organic gardens. The one I’ve used is the brand Thuricide, and it is for managing caterpillars. This includes those Cabbageworms and loopers, tomato fruit worms and hornworms, and cucumber pickleworms. It should also include Squash Vine Borers, but the success I’ve seen with these is patchy. For the vine borers, I have had better success when using several strategies together, rather than relying on just one (see link in “change the crop” section below).

Less simple pest control strategies

This next set of strategies includes practices that require either more thought or time or that require more than one “step” to complete.

Encourage beneficial insects (predators)

Many garden helpers, such as ladybugs, predatory wasps, and lacewings, are attracted to areas that have nectar-providing flowers nearby. Growing flowers like white clover, chives, hyssop, comfrey, or viper’s bugloss in the garden or in nearby areas can attract these helpers to your yard. Dandelions are another favorite.

The predatory insects also need a source of water, such as a very shallow birdbath that includes rocks or sand (to help them climb out, if they fall in).

Change the timing of your planting

beans and small purple bean flowers growing on a bush bean plant — A bush bean patch can make a lot of beans before beetles arrive to destroy the plants.

Mexican Bean Beetles can strip all the green tissue off bean plants pretty quickly. They aren’t a problem every single year, but some years they totally halt production of beans in the garden because they’ve actually killed the plants.

These pests don’t typically become abundant in my garden, even in a “bad” year, until July. That means that early-planted bush beans have ample time to make a great crop and then be removed from the garden completely after the gardener has harvested plenty of beans for fresh use and more to either can or freeze for later use.

If your garden has had a couple of bad Mexican bean beetle years, this strategy can be a great work-around for the problem.

A similar strategy of changing the planting dates, based on when a particular pest seems to appear, can work for other crops, too.

Change the crop

One mature, buff-colored butternut squash and one green, immature butternut squash, growing next to each other on a vine. — Butternut squash resist damage caused by squash vine borers.

Around mid-summer, gardens across the area are filled with wilted squash plants. Most of these plants are dying (or dead, with a gardener nearby holding a watering can and a hopeful expression on his or her face) from damage caused by the squash vine borer.

It turns out that we grow four main species of squash for food: Cucurbita pepo, Cucurbita mixta, Cucurbita maxima, and Cucurbita moschata. Of these, the C. pepo group contains most of the squashes we like to grow and eat: zucchini, summer squash, acorn squash, spaghetti squash, and most pumpkins. Sadly, this group is highly susceptible to squash vine borers.

The C. moschata group has the best resistance to the borers. The most familiar representative of this group may be the butternut squash, but this group also contains the cheese squashes, ‘Seminole Pumpkin’ squash, and a variety of squash sometimes called ‘Trombocino Rampicante’ (sometimes also called ‘Zucchetta’) that, when immature, is somewhat similar to zucchini.

Most of the C. moschata plants can grow to sprawl across 20-30 feet of garden. Gardeners working in smaller spaces can look for a dwarf version, like a dwarf butternut.

Not all insects are pests

For new gardeners, becoming comfortable with the universe of insects that inhabit the garden can take some time. It might help to remember that some of these creepy-crawlies are working with you, not against you.

Pollinators

Some insects are the pollinators that help your crops make delicious food for you to bring into the kitchen. Pollinators include many kinds of bees, butterflies, wasps, beetles, and flies.

The babies of butterflies are caterpillars, which do eat plants. This means that gardeners should determine some level of acceptable damage, not killing every caterpillar on sight, so we will have plenty of butterflies. Planting some crops specifically for caterpillars may help.

The ones that are wimpy eaters

Some insects that eat plants never become abundant enough to keep your plants from making good food. The caterpillar called the bean leaf roller is usually one of these. These may not be “garden helpers” like some of the other creepy-crawlies, but they aren’t exactly the bad guys, either. I usually leave these alone.

Predators

Saddleback caterpillar almost covered up in the white eggs of a parasitic wasp. — Some wasps lay eggs on caterpillars; baby wasps that hatch will eat the caterpillar.

Becoming familiar with the predators (wasps, ladybugs, lacewings, and their babies) can help you avoid killing them by mistake. Of course, the predators are not all super-choosy about their prey, so some of them may eat others of your beneficial insects. Try not to worry about that too much.

The caterpillar covered with wasp eggs in the picture nearby is a saddleback caterpillar. This type of caterpillar has stinging hairs that are very unpleasant for people to encounter.

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When to Harvest Summer Squashes

1 June, 2019 by amygwh

The summer squashes are the ones we grow to eat soon after harvest; they are not “storage squashes” like pumpkins and butternuts. For most purposes, we want to harvest the summer squashes while they still have thin skins, tender flesh, and soft seeds.

To achieve this ideal, a gardener needs to pay attention to the garden. Squashes can reach the perfect point for harvest one afternoon, then have zoomed past it by the next morning.

However, bringing good food into the kitchen is an essential part of gardening, so a little vigilance can be worth the effort.

Smaller squashes are often best

Yellow straight-neck squashes in various stages of maturity still growing on the plant. — Yellow straight-neck squashes are best when harvested small.

Some gardeners plan to eat their summer squashes raw. The veggies may be added to salads or sliced to use in scooping up dips. If “raw” is the goal, then harvesting squashes while they are small is a good practice.

As the squashes grow, they become tougher, the skins thicker, and the seeds chewier. But how can we know when the turn to toughness happens?

Some seed packets, for some varieties, provide information about when-to-harvest for the best flavor, but not all do. The guidelines below, for many kinds of summer squashes, are pulled from University Extension Service publications (from Clemson, NCSU, UGA) and from seed packets.

Yellow summer squashes, straight-neck and crookneck

Most of these will have the best quality if they are harvested before the fattest part gets more than one-and-a-half to two inches across, and while the squashes are still shiny. The first yellow squashes are usually ready for harvest about a month and a half after planting.

As the squashes mature, the skins turn dull and thick, the seeds harden, and the flesh loses its buttery tenderness. The sign that is easiest to see besides size is the loss of gloss from the skins. This doesn’t mean that larger, duller squashes are not ok to eat! However, it does mean that preparing them for use in cooking may need another step or two beyond simple slicing.

If the seeds seem tough, scoop them out before using the fleshy part in cooking. If the skin has turned weird (it happens), peel the squash before using the rest of it in your recipe. The result may not be the same as for a squash harvested at the “peak of perfection”, but it can still be good food.

If you leave larger squashes on the plant for more than a few days, the plant will slow down in making more squash. This is a good reason to check your squash plants often!

Regular Zucchini

Freshly harvested green beans and two green zucchinis in an oval basket. — Most zucchinis are best when harvested before they get more than about eight inches long.

Most varieties of zucchini should be harvested before they grow longer than about eight inches. I usually grow ‘Black Beauty‘, which gets mixed reviews from other gardeners, but it has excellent flavor, and I like the contrast of the dark-green skins with the pale inner flesh.

Round Zucchini

Round zucchinis like ‘Ronde de Nice’, ‘One Ball’, ‘Eight Ball’, or ‘Tondo di Piacenza’ should be harvested before they get any larger than a baseball. These little veggies are great for stuffing, and the smaller sizes, at two to three inches in diameter, seem to work the best for that purpose.

A reviewer on Baker Creek’s catalog website says that ‘Ronde de Nice’ survived squash vine borers and squash bugs longer than other squashes in his Arkansas garden. I haven’t tried this variety yet to find out whether the same is true in my garden in Georgia.

Scallop-edged squashes

Many scallop-type squashes, also called pattypans, should be harvested when they are between two and four inches across. However, the recommended harvest-size for ‘Scallop Early White Bush’ is much larger, at six-to-eight inches across.

This variation in recommended harvest-size is a good reason to save your seed packets, so you will have the information handy. If the seed packet is already lost, or doesn’t include the information, check your seed catalogs for best size-at-harvest for the variety, or search online.

When what a gardener really wants is a green “baseball bat”

Years ago, it never would have have occurred to me that a gardener might actually WANT an enormous, super-tough zucchini. My experience had been that we all ended up with a couple of these, even in small gardens, because zucchini plants can be huge and finding the squashes can be difficult.

Zucchini plants in a long garden bed, with corn growing at the far end. — It is easy to miss finding overgrown squashes when they are on large, bushy plants.

When I find one of these green baseball bats in my own garden, I scoop out the seeds, then grate the rest to use in zucchini bread or croquettes. However, huge zucchinis have never been my main goal. Then I met a couple of gardeners who let their zucchinis grow to hugeness on purpose.

They wanted the big, tough vegetables to make mock-apple pies. When they first explained their goal, I was skeptical, but I found several recipes online, which meant that these gardeners were not the only ones using zucchini in sweet pies.

To find out what I was missing, I used one of their big, tough zucchinis to make a pie (an example recipe is linked here) and took it to work to share with my co-workers. Everyone was amazed by the similarity to actual apple pie.

The texture of the big zucchini was a near-perfect match for the texture of cooked apples, and the cinnamon, sugar, and lemon were enough to match the flavor.

If your squash plants are not doing well

Here in the South, it is common for summer squash plants to last for only part of the summer. By mid-summer, they may have been attacked by pests and diseases that they cannot survive.

For help with problems that summer squashes can experience in the South, like squash vine borers, squash bugs, and mildew leaf diseases, see the article Summer Squash in the Southern Garden.

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When Compost is the Fertilizer

26 May, 2019 by amygwh

Years ago, I somehow got the idea that a product wasn’t a fertilizer unless it had a guarantee of its N-P-K ratio (nitrogen – phosphorus – potassium) on the label. This idea totally contradicted my personal experience of growing vegetables in mounds of nearly pure compost.

An early experience with “composted humus and manure”

Back in the early 1990s, when Joe and I first got serious about gardening in Georgia, the red clay in our yard was a major obstacle to success. I had been reading about gardening — mostly information from up North — that said: if you can grow radishes, you can grow tomatoes.

Pink radishes with leaves, on the grass next to a pair of garden shears. — Radishes are a beloved crop at my house, probably partly because we couldn’t grow them for so long!

The problem, of course, was that we couldn’t grow radishes. We added our own yard-compost to the garden, which included bags of leaves and grass clippings from our neighbors’ yards, to make more compost. However, improving the garden-soil/clay to a more loamy texture was slow.

At the time, we had small children and a tight budget. Buying enough amendments to improve the whole garden in one season was not really an option.

About the third year (could have been the fourth), I bought some commercial “composted humus and manure”, in bags, at a garden center. There was no N-P-K information on the label. The stuff was stinky, which means it was not completely composted, and it contained some large, suspicious-looking lumps (wads of cow poo?), but it was cheap.

My method was unorthodox, I am sure: I dug shallow holes, like saucers, a foot-and-a-half or more wide, in the garden, then dumped on about a half a bag of the “composted humus and manure” per hole for big plants like tomatoes and squashes, and about a third of a bag per hole for smaller plants like peppers and cucumbers. Luckily, the garden at that time was small, so not too many bags were involved.

Cluster of small tomatoes just beginning to form. — Tomato plants need more nutrients than some other crops for good production.

The holes were shallow enough that the composted stuff made low mounds. I pushed my spading fork through each mound a few times, to break up the interface between the compost and that red clay, then, I planted right into those stinky mounds.

Our plants grew, and they made plenty of vegetables. Around the middle of July, I dumped about a quarter bag of the same “composted humus and manure” around each plant as a side-dressing to provide additional nutrients, to keep that productivity going.

At the time, buying the compost meant that additional fertilizer didn’t fit in our budget. All the nutrients for plants in the garden came from the yard-compost, which was distributed throughout the whole garden, and the mounds of composted humus and manure.

What counts as fertilizer?

Greensand is a good sources of potassium for organic gardens. — Greensand is a concentrated source of potassium, with an N-P-K of around 0-1.5-5 .

The definitions of fertilizer vary, but there is general agreement that a fertilizer contains elements that improve plant growth and productivity; they are given to plants to help them grow.

I usually think of fertilizers as being products that are concentrated sources of plant nutrients. Examples are sul-po-mag for potassium or blood meal for nitrogen. You can buy these in little bags or boxes, and a cup or two in a small garden can be enough to support good plant growth, if potassium and nitrogen are in too-low amounts in the soil.

Composts, though, are typically added by the wheelbarrow-load, instead of being measured in cups. They do not seem to be concentrated sources of nutrients.

Nutrients in compost

Information from the University of Massachusetts says that most finished composts have an N-P-K ratio of about 1-1-1. The numbers tell the percent of that nutrient in the product, so a product that has an N-P-K of 1-1-1 contains 1% each of nitrogen, phosphorus, and potassium.

These are low amounts, considering that a standard chemical fertilizer recommended for home gardens is 10-10-10, which contains 10% each (ten times more!) of the three major nutrients.

In addition, Iowa State University’s article on the Do’s and Don’ts of Composting cautions that compost should not be considered a fertilizer, because the release of nutrients from compost is slow. Again, though, my experience was that the compost was enough.

One advantage of composts is that the nutrients N-P-K are not the only nutrients they provide. Since composts are made of broken-down plants, they also can contain magnesium, zinc, boron, iron, and other essential plant nutrients — that the original plants were made of — that support plant growth.

Is compost safe?

Safety for people

Composts made from animal manures, if they are not completely composted, can contain pathogens that are dangerous to humans, like E. coli and Listeria. Most home-made composts will not contain manures, which lets most of us cross that off our lists of potential hazards.

However, home compost piles will contain a wide range of bacteria and fungi that can cause allergic reactions in some people. Cornell University’s Waste Management Institute recommends that susceptible individuals wear dust masks when turning the compost on dry/windy days.

Safety for the garden

Composts made with bio-solids (treated sewage sludge) can contain more heavy metals than are safe, especially when compost is used in very large amounts (from report posted on Cornell University website). Home-gardeners who are filling raised beds with purchased, all-compost mixes may want to check the origins of the compost, to see if bio-solids are in it.

Composts can also contain fairly high amounts of soluble salts (See the U. Mass article on compost use and soil fertility). This is not normally a problem in gardens and fields that receive adequate rainfall, but in greenhouses or high tunnels where the soil doesn’t get good, drenching rainfall, the salts can be a problem. Mushroom compost, especially, can be high in soluble salts (see table in Oregon State University’s pdf about organic fertilizers).

If your garden has received many loads of compost, but productivity seems to be dropping, consider having the soluble salts level in the soil checked through your local Cooperative Extension office.

Interesting bits I learned while looking for good resources about “compost as fertilizer”

Tom Thumb lettuces in the Spring Vegetable Garden — Lettuce is a known bio-accumulator of some heavy metals.

The odor/aroma of finished compost, like a damp log that is decaying in the forest, is caused by the action of actinomycetes, which are a kind of beneficial bacteria. (From a chapter summary on this webpage from ScienceDirect.)
Lettuce, spinach, and celery are three crops that can accumulate heavy metals in higher amounts than other crops. (From a Cornell University paper about compost guidelines.)
In some places in the U.S., composting food scraps aboveground is not allowed. (University of Maryland article about how and why to make compost.)
Compost is known to suppress some plant diseases, but if nutrient levels are high, the ability of compost to hold down diseases is reduced. (Chapter summary from ScienceDirect.)

Why am I thinking about this now?

I have a bag of Soil3, a cubic yard of compost, that I’ve been using to amend my garden with this summer. It reminded me of the olden days, when I grew some of my crops in little mounds of compost. The good news is that the stuff in my pile of Soil3 is not at all stinky!

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