pest control

Protect Seedlings with Paper Collars

24 April, 2020 by amygwh

When I planted part of my new garden a few weeks ago (zone 9a!), the seeds set directly into the garden included zucchini and cucumber seeds. The cucumbers all came up, but no zucchini plants appeared.

I checked the zucchini seed packet — it was stamped for use in 2019, which is plenty recent, and it was stored in the same container, in the fridge, with the other seed packets. The zucchini seeds should have been ok.

There was no sign of critter activity above ground. No holes had been dug, no remnants of the seeds were visible nearby. When I dug down to look for the seeds, they were just gone.

Zucchini seedlings coming up within protective collar. — Seedlings in paper cup collar.

I suspected a critter, but the below-ground kind, something similar to a cutworm.

To verify this idea, and to thwart a future loss, I planted the next set of zucchini seeds inside collars that I made by cutting up a saved paper cup.

I pressed the collars into the garden soil and planted a couple of seeds in each one. The good news is that the collars worked. We now have little zucchini plants.

If your garden experiences a similar seed failure, consider using the paper collar method of protecting seeds and seedlings. First, though, consider some of the many other reasons that the seeds might not be sending up little plants.

The actual seeds

Seeds need certain conditions for them to stay “viable”. If the seeds are old or were held in poor conditions for too long, they may have lost their ability to grow. Ask these questions:

Seeds in their storage box, with a gasket-type seal, to use in planning this year's garden. — Seeds in storage box.

How old are the seeds? Seeds for some crops are only “good” for two-to-three years. If the seeds are older, they might not be able to grow.
Have the seeds been kept in cool, dry conditions? If seeds have been exposed to warm, humid air for long (like being left in a hot car for a few hours sometime last summer), then they might not be able to grow.
If the seeds are from older packets, not newly purchased this year, have they been stored properly? Vegetable seeds keep their ability to grow longest when they have been stored in airtight containers in the fridge or freezer.

Planting and care of the seeds

Planting depth, soil moisture, and soil temperature are three factors that can have a huge effect on whether seeds will unfold into little plants that are able to push up to the soil surface.

One big reason for seeds to not come up is that they have been planted too deep. Think back to the day of planting. Does the planting depth match what is recommended on the seed packet, or did the seeds get pushed, or slip down, more deeply into the soil? Seeds that are too deep may unfold down under the ground, but they might not be able to push up through all that soil to the surface.
Was the soil kept evenly moist? If the garden soil dries out, seeds will not come up. If the soil dries out after the seeds begin to unfold, the little plants will die before you ever see them. Soil that is too wet is just as bad as soil that is too dry. Seeds and their unfolding little plants can drown and/or rot in soaking-wet soil.
Was the soil warm enough? Some seeds need warmer soil than other seeds. If you are still waiting to see your okra plants, for example, be prepared to wait a while longer. Okra seeds unfold faster in warmer soils.
Have you waited long enough? Some seeds take longer than others to come up, even with the right warmth and water conditions. For example, parsley seeds can take a couple of weeks (or three, or four) to unfold their inner plants.

Critters

A gardener can have done everything right, using excellent seeds and providing perfect care to the garden, and still not see the expected little plants emerging from the soil. After thinking back carefully to consider where else in the steps something could have gone wrong, the gardener may then need (like me) to consider critters as a possible cause.

Seedling in the garden, with its leaves bitten off. — Common type of critter damage.

A wide range of critters dig up and eat seeds, both the newly planted seeds and the seeds that have begun to unfold into little plants.

The helpful thing about most critters is that they tend to leave signs, or clues, about who they are.

Some birds will scratch up seeds to eat, and crows, in particular, will pull tiny plants (especially corn) out of the ground. You may see tossed-aside leaves that are their left-overs.
Small mammals, like chipmunks, rats, and squirrels sometimes dig up seeds and seedlings to eat. They may leave holes in the ground, or dirt may be kicked up around the planting area. Sometimes, too, they leave footprints.
Rabbits and deer may bite off the tops of the plants, leaving a shortened stem standing in the garden.
Underground pests, like cutworms, can destroy seedlings, and other similar larvae can eat the softened seeds. The damage from these may be harder to spot.

Paper collars when there are no cups

Paper cup cut apart to make protective collars. — Paper cup collars for seedling protection.

When I have planted corn inside collars, the birds have left it alone. Corn was the first crop that I protected in this way.

In a small garden, using paper collars to defend your seeds and seedlings is not too much work. Finding enough material to use is the biggest challenge. Right now, we are short on saved paper cups.

However, my Louisiana sister told me this morning that she has used paper-towel tubes and toilet-paper tubes, cut to shorter lengths, to protect seedlings in her garden.

I am pretty sure I can find some cardboard tubes to cut into shorter lengths (an inch-and-a-half or two inches), which is good, because I have more seeds and little plants to set into the garden this weekend.

I hope you are all keeping safe and well and enjoying your gardens, no matter how small.

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.

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.

Summer Squash in the Southern Garden

11 June, 2018 by amygwh

One of my most-favorite lines ever in a UGA Extension publication is about summer squashes. The line is in a table that lists recommended varieties for each type of crop. It says, for which varieties of summer squashes (including zucchini) to plant in the garden, “all are good and easy to grow.”

This line still makes me laugh. In a way, it matches my experience. In early summer the plants look great and produce plenty of flowers and small squashes. Unfortunately, it could also read “all are finicky and frustrating to grow”, since many summer-squash plants seem to drop into wilted piles of yellowing leaves in mid-summer, long before we have eaten too much squash. When I first started gardening in Georgia, I was lucky to get five or six good-sized squashes from a plant before it keeled over.

Southern Vs. Northern Experiences with Summer Squash

I am not the only Southern gardener to be troubled by a too-small squash harvest or plants that die too soon. However, Northern gardeners do not seem to have this problem. The complaint I hear from Northern gardeners is quite the opposite – they have mountainous harvests of zucchini and yellow squashes that keep coming all summer long.

Really, the complaint is one that doubles as a brag – their squashes are so very productive that, when the harvests begin, it is risky to leave your car windows open. The risk is that gardeners who have a superabundance of squash are likely to drop a large bag of squashes into the car as “a gift”.

Legend has it that over-squashed gardeners also will fill a bag with squashes, hang the bag on the doorknob of an unsuspecting neighbor’s home, ring the doorbell, and run. By the end of August, people are totally tired of squashes, especially zucchini.

I have never had so much summer squash and zucchini that I was not happy to find another one in the garden. Happily, as I have gained experience and understanding of what is going on in the garden, my plants survive longer and the harvests are larger. I have found that it is possible to have plenty of summer squash in the Southern garden, with a little planning.

Problems with Summer Squash in the Southern Garden

Squash Vine Borers

These are the cause of much anguish in the squash patch. The borers are larvae (caterpillars) of a day-flying moth that lays its eggs on stems of our squash plants. When the eggs hatch, the babies bore into stem, where they eat the soft part of the inside of the stem. The borers seem to not eat the toughest fibers, because one sign that borers have caused your squash plants to wilt is that the stem looks frayed. You may also see some frass (caterpillar poo), a golden-orange-brown, granular-looking mush, around or in the damaged section of stem.

What to do? If the plant is already a wilted mass of yellowing leaves, it may be too late to save the plant. If, though, you look at the lower part of a squash stem, see little holes in the stem and maybe a little frass nearby, but the plant looks otherwise healthy, it is not too late!

Step 1:

Locate the sharpest blade on your pocket knife and use it to make a long slit in one side of the squash stem. The slit should run lengthwise on the stem; it should start below where the damage seems to be and extend above the damaged area. Use the tip of the knife blade to pry the slit open, so you can look inside and find the squash vine borers. Use the knife tip to remove (or kill, depending on your philosophical stance on garden pests) the borers from the stem. You might find just one, but you might find a half dozen or more.

Step 2:

Saturate the inside of the stem with a product that contains Bt for caterpillars (Thuricide is the brand I have been using – bought a few years ago and still works), and spray up the length of the stem on the outside, too. If any borers are still alive inside the stem, the Bt for caterpillars (organic approved) should reverse that status fairly soon. If your Bt is powder form instead of liquid, do your best to fill the stem with the powder, and then liberally apply it along the outside of the stem.

Any Bt applied on the outside of the stem will wash away in the next rain or watering-event, so you might want to re-apply it a few times.

Step 3:

Mound up garden soil over the damaged section of stem. If you are feeling very industrious, you can try wrapping the damaged section with aluminum foil, but I find that just piling up some good soil over the damaged stem protects it from invasion by other pests. Also, squashes sometimes will send out new roots along buried sections of stem.

Step 4:

Consider the health-status of your plant. Summer squash in the Southern garden should be lush, with huge, dark green leaves. In my garden, the largest, fastest-growing squash plants survive squash vine borer damage much better than less-lush plants. If your plants are on the puny-side, side-dress with some organic fertilizer or a shovel-full of compost or composted manure.

Squash Bugs

Squash bugs look a lot like stink bugs as adults. As youngsters, they are called nymphs, and they move around in groups. The nymphs do not look at all like the adults, but if you see groups of insects scuttling around on your squash plants, they probably are squash bug nymphs.

Squash bug eggs on a leaf of summer squash in the Southern garden — Squash bug eggs on a leaf. PHOTO/Amygwh

These feed on the squash plants – leaves and fruits – and they can cause a lot of damage. An even bigger problem is that they can carry a squash disease called Cucurbit Yellow Vine, which can definitely kill your plants.

The adults and nymphs can be removed by knocking them into a tub of soapy water. It is a good idea, though, to check your plants for squash bug eggs.

You can use a piece of clear packing tape or a piece of duct tape to remove the eggs from your plants. Just press the sticky side of the tape to the collection of shiny eggs, remove the tape, fold it over, and smash the eggs inside the tape. Simple!

Removing all the eggs will help keep the population of adults and nymphs to a much lower level, which will limit the amount of damage they can do to your plants and reduce the risk of Cucurbit Yellow Vine.

Mildews

Summer squash in the Southern garden also is attacked by mildew diseases, both downy mildew and powdery mildew. If your plants die earlier in the summer, then these will not be a problem, because the mildews usually appear after mid-summer.

Downy mildew arrives at a slightly different time each summer in upper parts of the South. It can’t survive our winters, but it comes up from Florida where it survives just fine. If the petioles (leaf stems) are still standing up on your plants, but the leaves look brown and droopy, then downy mildew is a likely cause. There is no effective spray or treatment for downy mildew, but preventive care can help.

Leaf diseases like downy mildew (and powdery mildew) need leaf wetness to infect the leaves and grow. Keeping the leaves dry as much as possible, by careful watering, can delay infection. Increasing air-flow around the leaves, so they dry faster after a rain, also helps. Remove weeds as much as possible, and allow plenty of space between plants.

Also, healthy, well-grown plants get less disease than puny plants. Just like for squash vine borers, consider whether you might need to side-dress your plants with fertilizer or compost to improve their condition.

Powdery mildew becomes a big problem in warm, humid conditions. Since that pretty much describes several months of weather across the entire Southeast, it is a safe bet that powdery mildew will find your plants eventually.

Treating Mildews in Organic Gardens

For both downy and powdery mildews, the bacterial product Serenade, which is organic-approved, can slow down the rate of infection. It should be applied to plants every 7-10 days, before any sign of infection is seen. If you see signs of disease on your plants (mottled or brown spots on leaves, for example), it is too late to get much benefit from using the product.

In a couple of Cobb County community gardens, the use of Serenade has helped extend the “squash season” for local gardeners. If your squash patch has suffered from mildew attack in past years, you might consider trying the spray, but do not wait much longer to start. By July, infection may already have begun.

Another option is to spray with homemade products of either compost tea (one gallon of well-aged compost in a five gallon bucket filled with water, soaked for three days, then strained to use in a spray bottle) or a baking-soda spray, both of which can slow down an infection. Neither of these has been shown to work as well as Serenade (which works less well than chemical fungicides), but some gardeners like to try the DIY route first.

If you are a DIY gardener, this is the recipe for baking-soda spray recipe from one of my Rodale gardening books:

Dissolve 1 teaspoon of baking soda in a quart of warm water, with up to a teaspoon of dish soap or insecticidal soap added. Spray the leaves, including the undersides.

If you would rather treat your garden crops with compost tea but do not currently have a source of good compost, try the Sustane Compost Tea Bags. Not-needing to strain the finished compost tea before using it in a spray bottle makes the “tea bags” extra-convenient.

For both compost tea and the baking soda solution, apply to plants much more frequently than the Serenade.

Hoping for Plenty of Summer Squash from the Southern Garden

Summer squashes seem to be an essential vegetable in the South. They are the base of many favorite “church casseroles” – dishes that fill the tables at summertime potluck suppers and appear at your door in hard times. I don’t remember seeing squash-casseroles when I was growing up in Oklahoma, but I certainly have seen (and enjoyed) many since moving to Georgia. In the South, the squash harvest is important.

The garden/farm where Joe and I used to volunteer got around squash-plant losses by planting MANY squash plants over several weeks. Even when some plants died, more remained and produced squash. If the squash harvest didn’t look abundant enough, we just planted more.

In home gardens, this approach is not really feasible. Hence, the long blog post about upcoming problems with summer squash in the Southern garden.

Best wishes for a squash-filled summer!

-Amy

Aphids on the Arugula?

12 February, 2017 by amygwh

One of my friends brought some arugula leaves to the office last week, to show me the many hundreds of aphids that were on them. The arugula is growing at a community garden that she had visited, and she had permission from the gardener to pick a few leaves.

Aphids on arugula from local community garden. PHOTO/Amygwh

We slid the leaves under the microscope and could see that, while a whole lot of the aphids are alive and active (the green ones in the picture), some had been “parasitized” by a wasp.

That means that a little wasp had laid an egg inside the aphid, and the egg was developing into a new wasp.

The aphids that have a baby wasp inside are the puffed-up golden ones in the picture.

When each wasp-baby is mature, it will bust out of the aphid body, leaving behind an empty aphid shell.

Are images from “The Alien” movie flashing through your mind yet? Sometimes, real life is just as weird as science-fiction movies. This is part of what keeps gardening so engaging.

In organic gardening, knowing that there are predators and parasitic wasps around, waiting to take care of a pest problem, provides an odd kind of comfort. Unfortunately, though, even if a swarm of ladybugs (surprisingly effective predators on aphids) moves in to help the wasps clear up the aphid problem, this arugula is going to need a lot of washing before it is added to a salad.

My venerable copy of Rodale’s “The Organic Handbook of Natural Insect and Disease Control” (my copy is from 1996) offers some help for aphid infestations. The first suggestion is to wait for the predators to take care of the problem. Usually, in my garden, “waiting” is enough.

This is an odd year weatherwise, though, so it looks as though more active steps will be needed in some gardens. The next suggestion is to blast the little plants with strong spray from a hose to knock the aphids off. The next after that is to try an insecticidal soap spray. In a dire emergency, try a veg-garden-pest spray that contains neem.

Of course, the very first thing to have done, if anyone could have foreseen the aphid disaster looming from back in the fall, would have been to cover the little crop with a spun rowcover to keep the aphids out completely.

Hoping that other gardens are relatively aphid-free!

Field of Greens

18 November, 2015 by amygwh

At the little farm where Joe and I volunteer on Saturday mornings, the lower field has so many rows of greens – mustards, collards, radishes, and a little bit of kale – that there is no way for us to fully harvest the crop.

The guys who manage the farm, who pay attention to the farming lore of local old-timers, plant the field each fall from end-to-end knowing full well that many perfectly good greens will go uneaten, just like in years past. For them, even though they enjoy eating greens, the main point of that crop is not so much Food as it is Pest Control.

They call those greens their “fumigant crop”, and it is planted to keep the root-knot nematodes at bay. In spring, when they are ready to plant the warm-weather crops, they just turn under all the remaining greens to let them finish their good work of pest-control. Not too surprisingly, research supports the practice of the old-timers.

The book Managing Cover Crops Profitably, published by SARE (3rd edition, 2010), which can be downloaded for FREE, cites research that demonstrates the “nematicidal effects” of Brassica-family plants like mustard greens and radishes.

When I was talking with a county resident last week about his garden, he mentioned that he’d been having trouble with root-knot nematodes in his 1.5 acre garden over the past couple of years. I told him about my friends and their field of greens, and he went silent for a minute. Then he said that he hadn’t planted greens as a winter crop for the past few years because his freezer was full, but he had in each of the previous 20 or so years of gardening in that spot.

I am pretty sure that, regardless of the state of his freezer, next September my new gardening friend will be planting a whole lot of greens.

Squash Beetles and Bean Harvests

2 June, 2015 by amygwh

Squash beetles look a lot like pale ladybugs.

It looks like a “good year” for squash beetles, because I have smashed a lot of them already. They are on both the zucchini and cucumber plants.

My camera hasn’t wanted to focus on the little beetles, so the picture at the right is a bit fuzzy, but if you imagine a “washed out” looking ladybug, with seven spots on each side of its body, and it is eating a plant in the the squash/cucumber family, then you pretty much have a good picture in your mind.

The pattern of damage on the leaves is distinctive. According to Purdue U.:

Squash beetles snip an arched line around their feeding spots.

“The squash beetle larvae and adults usually feed on the underside of leaves and snip a circular trench that arcs from one leaf edge to another. After it has completed the trench, the insect feeds on the tissue isolated by the trench for 1-2 hours before searching for another leaf.

A study at University of Delaware showed that this feeding characteristic reduces the influx of chemical defenses from the injured plant to the entrenched tissues, thereby preserving the leaf tissue’s suitability for feeding.

Moreover, the larvae only feed on the tissue between veins on the underside of the leaves, leaving the upper surface more or less intact. As a result, their feeding gives the injured leaf a characteristic lace-like skeletonized appearance on the upper surface.”

Saturday’s harvest.

The good news is that this isn’t the cucumber beetle that carries bacterial wilt or the squash bugs that transmit the cucurbit yellow-vine virus.

Hunting squash beetles to smash is easiest and most productive in the middle of a sunny day, when they are most active, but I have been scouting for beetles (and then smashing them) after I get home from work, after walking the dog and tending the bunnies, while I am in the garden to harvest beans.

Sunday’s harvest.

The bean harvests are going well. After the great harvests of the weekend, I was able to blanch some of these for the freezer, for future meals.

There will be more zucchini coming to the kitchen over the next couple of days, and Joe and I are both snitching black raspberries off the canes while we are out in the yard. When the Heritage red raspberries start to ripen, we will begin to have enough berries to bring inside before eating them (there aren’t many black raspberry plants in the yard).

Blackberries are all still green, but they also are looking good.

I hope all the other gardens out there are producing well and are untroubled by pests!

Benefits of Crop Rotation

28 August, 2013 by amygwh

I have understood for a pretty long time that crop rotation, which involves the practice of NOT planting the same crop (or crops in one plant family) in the same location year after year, is important for a variety of reasons.

One reason is that plants in one family often are attacked by the same pests and diseases. Rotating out of a particular space, and planting crops from a different family there instead, can help reduce the buildup of diseases and pests that attack crops in one plant family.

Another reason is that plants in one family often make similar nutrient demands on the soil. Jessica Strickland of North Carolina Cooperative Extension, in a May 2013 article, wrote:

“Vegetables in the same family are similar in the amount of nutrients they extract from the soil, so over time planting the same vegetables in the same spot can reduce certain nutrients in the soil. If the same family of vegetables is planted every year in the same location, insect and disease problems continue to increase and soil fertility drops. Using pesticides and fertilizer could provide little help but over time they would not be able to keep up with the increasing problems.”

Also, rotating to some particular crops can help reduce a pest problem that already has built up to damaging levels. An example pest is root knot nematodes, which can lower productivity of a crop pretty dramatically – if they don’t actually kill the plants outright. A population of these soil-dwelling pests can be lowered by planting a bed solidly in one of the nematode-repelling marigolds or in a grass-family crop like rye, wheat, or oats.

What I didn’t know until recently is the effect of crop rotation on the diversity of soil microbial life, the maintenance of which is so integral to successful organic gardens. In the Science Daily article “Why crop rotation works: Change in crop species causes shift in soil microbes“, Professor Philip Poole of the John Innes Centre in England is quoted as saying,

“Changing the crop species massively changes the content of microbes in the soil, which in turn helps the plant to acquire nutrients, regulate growth and protect itself against pests and diseases, boosting yield.”

Professor Poole added: “While continued planting of one species in monoculture pulls the soil in one direction, rotating to a different one benefits soil health.”

Yet another good reason to plan a careful rotation in the veggie patch.

Gardens and Talks

22 July, 2012 by amygwh

This week I spent a couple of hours at a community garden in Smyrna, and it was mostly doing very well. It was great to see so many little gardens, and to meet more people who are focused on growing good food!

However, the garden was definitely having a pest problem. I have never seen so many beetles-per-square-inch before; these are kudzu bugs, and they were all over the pole beans:

So far, there is no good, established control method for these beetles, since they are new to the United States. Scuttlebutt has it that some entomologists at UGA are looking into the effectiveness of a parasitic wasp, but that’s really all I’ve heard so far. It is likely, though, that if next year gardeners grow their beans under row covers, they will be able to avoid (or at least delay) such dramatic infestation.

The garden’s tomato plants also had a problem, and I’m pretty sure it is Septoria leaf spot. The good news is that most of the garden beds already have produced a lot of tomatoes for the gardeners, so they have enjoyed a good harvest up to now.

The garden/farm where I volunteer on Saturdays has the same disease problem, and I’m guessing that it’s only a matter of time before the leaf spot hits my garden, too. Disease has been a huge problem for gardens all over the area this year. Gardeners who are not all that concerned about using organic methods have been keeping the manufacturer of Daconyl (a fungicide) in business this year, and the rest of us are muddling through as best we can.

I pulled out the last of my Cherokee Purple plants yesterday, but I have several other tomato plants still producing, so I’m not totally heartbroken. Joe says that the Tomato Man’s Amish tomatoes taste better, which means we still have what Joe thinks of as a “highly desirable” variety providing tomatoes for us.

Later today I’ll get to visit another community garden, this one out in the north-east corner of the county, and I will be talking some about getting ready for planting fall veggies and about pest and disease problems.

On the evening of July 31, I’m scheduled to talk at the county Extension office about getting ready for the fall veggie garden. Anyone who wants to come should call the office to sign up (770-528-4070; or email uge1067@uga.edu).

Bad News Bugs

7 June, 2012 by amygwh

Just before I left town for another trip to Oklahoma, I saw three adults of the squash vine borer flitting among my plants, and I smashed two Mexican bean beetles in the bush beans. It looks as though the pests are going to be as early as the veggies have been! These are two pests that typically cause a lot of damage in my garden, and I know that my zucchini-days, especially, are numbered.

Also before I left town, I pulled up two tomato plants that were not thriving. The two were both Rutgers, which is normally my emergency backup, never-fail variety. Apparently, this gardening year is going to throw one curve after another at the veggie gardeners! When I pulled up the two plants, there didn’t seem to be anything overtly wrong. The vascular system looked clean (not gunked up with fungus) and the roots were un-knotted (no root knot nematodes); the roots were not vigorous, though, and the plants weren’t growing well. Since I don’t know yet what went wrong, I planted sunflowers in the spaces those plants were pulled from.

I got back home on Tuesday evening and didn’t have chance to do much more than take a quick look around the garden. Everything looked basically fine. But when I went around on Wednesday to check things out more closely, I saw that one tomato plant had been attacked by a pest:

The gaping holes and some black frass (poop) that had fallen onto some lower leaves were a huge give-away that the pest is one or more caterpillars, but I didn’t see any at first. When I leaned across to the next plant, though, I found one:

This guy is very bad news. He/she is an armyworm, and like the squash vine borer and the Mexican bean beetles, this pest has made an early appearance. My copy of the book The Organic Gardener’s Handbook of Natural Insect and Disease Control contains this somewhat alarming sentence about these caterpillars:

Larvae can consume whole plants in 1 night.

Needless to say, I have a date with a little sprayer full of Bt (the bottle I have is called Thuricide), the organic-approved pest control substance for caterpillars.

Even worse, when I was looking at the tomato-neighbor to the damaged plant, the plant on which I found the armyworm, I found some of these brown lesions on the lower leaves:

It’s a little faint in the photo, but the ringed brown spot indicates a disease called Early Blight, which means that this particular plant is a goner. Several leaves had similar lesions. After verifying the disease with my handbook (hoping that my first guess was wrong), I got out a pair of pruners and a big garbage bag so I could get this plant out of the garden.

The plant was big, and it already had nice big tomatoes on it – making the loss especially annoying – and it had to be cut up to be removed from the cage. Cutting through the stems was a revelation! The insides of all the stems were already completely brown, and the lower stem was mushy inside.

I haven’t decided yet what to plant in the space from which the diseased plant was removed. It shouldn’t be another tomato or tomato-family relative, but that leaves a lot of options open.

Happily, the biggest problem some of my plants have is that they are so overloaded with pretty flowers that they are falling over. Bee balm always reminds me of fireworks, but my husband thinks they look like Sideshow Bob, from The Simpsons.