Organics

Planting Dates for Summer Garden Vegetables

18 March, 2019 by amygwh Leave a Comment

As spring advances and weather warms, the urge to plant the summer garden becomes almost overwhelming. Knowing which crops can stand a bit of cooler weather and cooler soil can help us make good choices about what to plant when we just can’t wait any longer.

Understanding the last frost date

Most of the garden vegetables that we grow in summer are frost tender, which means that they won’t survive freezing weather. This is why most seed packets use the “last frost date” — the expected date of the last freezing temperatures — as a marker for when to plant summer crops.

Where I live, the average date of the last frost in spring is in mid-April. The date is not exact; we estimate the date based on the dates of the last frost in previous years. Annoyingly, we won’t know the exact date of the last frost for this year until we are well past it. Some years, the last frost in my yard is in March, and one year my yard had a frost on April 23rd.

The role of soil temperature

Cucumber seedling with three true leaves, already planted in the organic home garden. — Cucumber seedling transplanted into the garden in April.

Part of finding the best time to plant vegetables is knowing the best temperature for seeds to sprout and for plants to grow. Texas AgriLife Extension points out that these two temperatures are not necessarily the same. For example, bean seeds may sprout best at a soil temperature of 85 degrees F, but that temperature isn’t best for plant growth and productivity.

The AgriLife article lists reasonable, “compromise” soil temperatures for planting many crops:

cucumber (64°F)
cantaloupe (68°F)
okra (73°F)
pumpkin (75°F)
squash (70°F)
watermelon (72°F)
beans (72°F)
beets (45°F)
tomato (55°F)
turnip (50°F)
corn (55°F)

From the list, you can see that beets and turnips (cool-season crops) can do well in cooler soil, corn and tomato plants slightly warmer, and cucumbers and cantaloups a bit warmer still. This information can help in planning your schedule.

Recommended date ranges from University Extension programs

UGA publishes a Vegetable Planting Chart that shows suggested planting dates for garden vegetables. The dates are for middle-Georgia (a line through Macon across the state), which means that the dates need to be adjusted for areas north and south of that line.

Tomato transplants for the organic home garden, indoors under lights on a cold day.

For my area, just north of Atlanta, I would add about two weeks to the ranges in the UGA planting chart to get a reasonable planting date range for my garden.

North Carolina State University Extension publishes a planting chart for Western North Carolina. The dates are similar to those that I would use for my garden.

You may notice that the recommended date-ranges in the linked publications for spring planting can be quite large – up to six weeks for some vegetables. The whole range of dates might be good theoretically for a particular crop; however, for organic home gardens, there are some good reasons for choosing to plant either at the early end of the range or the late end.

Reasons to consider dates at the edges of the recommended ranges

For both bush beans and pole beans, I usually plant as early as I think the plants can survive the experience. The early planting — as early as the first week in April, if the weather forecast looks ok — means that I start harvesting beans before the end of May. By the time the Mexican bean beetles show up to demolish the plants, I will have harvested plenty of beans.

I also choose an early planting date for cucumbers, squashes, and melons. Those plants all are attacked by mildew diseases in late summer and an assortment of pest insects in mid to late summer. Early planting allows a larger harvest, before the plants are affected by whichever problem attacks first. For these crops, planting seeds in the first week in April, or transplants a week or two later (when the soil is warmer), can make a big difference in how much food I can harvest before the plants die.

Okra and sweet potatoes are two crops that I plant at the later end of the recommended planting date range. Both of those two crops grow slowly in cool weather, and I have found that keeping ahead of the weeds, which grow faster, is more work when these two crops are planted early. When okra and sweet potatoes are planted later, in early or mid May in my yard, they grow fast enough to shade the ground sooner, and weeds have less chance to take hold.

Tomatoes are another crop that I plant later than almost every other gardener I know. My experience is that later-planted tomatoes, like at the end of April or early May, are less troubled by blossom-end rot than earlier-planted tomatoes. They also are more likely to survive whichever soil-borne wilt disease is in my yard, and infection by the ever-present early blight disease is usually less severe.

Organic gardeners won’t use the chemicals that are available in garden centers to control all the above problems. Instead, we have be a bit wily about getting around the diseases and pests that can reduce the productivity of our organic home gardens. I have found that adjusting my planting dates to the edges of the date ranges, for some crops, is all the “control” I need.

Of course, keeping a good attitude about the vagaries of the natural world also helps.

Amy’s planting schedule

In case you are curious, this is when I plant the standard summer crops, most years, in my garden, zone 7B, just northwest of Atlanta:

first week in April – plant seeds for bush beans and pole beans if forecast is ok; if a freeze is in the forecast, I start these in a flat or tray, to transplant to the garden after a couple of weeks. I also start squash-family plants – cucumbers, zucchini, winter squashes, melons – in little pots this week, to transplant to the garden when the soil is warmer.
mid-April – plant corn, if any is planned. For me, that is usually popcorn. Early planting for corn reduces problems with corn ear-worm. Later plantings almost always have more ear-worms. Plant the transplants (beans, squash family plants) when the first true leaf is a couple of inches across.
late-April – plant pepper plants, and seeds for Swiss chard (if planned).
early May – plant tomato and eggplant transplants, seeds for okra.
mid-May – plant sweet potato slips.
mid-summer – plant Southern peas when one of the earlier crops comes out of the garden (bush beans or cucumbers are usually the first to go). After bush beans have been gone from the garden for a couple of weeks, if there aren’t any pole beans also in the garden to harbor more Mexican bean beetles, plant a new patch of bush beans.

What the above schedule doesn’t show is that I start tomato and pepper plants from seed, indoors, in early March. It also doesn’t include annual herbs, like basil or borage, or flowers, like nasturtium and Zebrina hollyhock, that I plant most years.

Protecting early-planted crops from frost

The summer crops are frost-tender, but I plant some of these crops early enough that the risk of frost is high. A couple of different strategies can be used to protect your crops.

The first strategy is the use of transplants to allow an early start for some crops, like beans and cucumbers. This strategy takes some planning, and it takes space in your house. It also, though, protects plants from cooler weather, since they are indoors. The plants can be planted into the garden when the risk of frost is lower.

The second strategy is the use of row covers to protect tender crops in the garden from a light frost. If a hard freeze happens and the row cover does not fully protect a crop, some replanting might need to be done. The good news here is that most seed packets contain enough seeds to replant a small home garden.

For further reading, my older post about planting seeds in the garden contains reminders about planting depth and plant spacing that might be helpful.

(If this post is helpful or interesting, please “like” or “share” it. Thank you!)

Broccoli, Beets, and Boron – Updated

8 March, 2019 by amygwh Leave a Comment

Soils in the region where I live are short on the mineral boron, an essential plant micronutrient. The University of Georgia soil lab doesn’t measure boron levels in its routine test for garden soil, but it does include a recommendation to add some to a home vegetable garden. This is the recommendation:

“Apply 1 tablespoon of borax per 100 feet of row to broccoli and root crops such as turnips and beets. This can be applied by mixing the borax thoroughly with approximately 1 quart of soil in a container and then applying the mixture along the row; or it can be mixed with a quart of water and applied to the soil in solution.”
University of Georgia, Soil Test Report, basic soil test for Home Vegetable Garden, 2018

What is a micronutrient?

Boron is one of several micronutrients that plants need. The micronutrients are needed in tiny amounts, but they are essential for plant growth. Other micronutrients include copper, iron, and nickel, among others.

For boron, the difference between not-enough and too-much is a pretty narrow range, according to K. Kelling at the University of Wisconsin and Ron Goldy at Michigan State Univ. Extension. This means that great care must be taken to not use too much.

How does boron help plants?

Golden beets growing in the garden - beets are a crop that need a little more boron than others. — Golden beets growing in the garden – beets are a crop that need a little more boron than others.

UMass Extension, Amherst, says that boron “is required for many different aspects of plant cell functioning, including protein synthesis, development of cell walls, carbohydrate metabolism and sugar transport, pollen growth, fruit set, and seed production.”

Sounds important, to me!

What happens when plants don’t get enough boron?

The UMass information about boron deficiency lists these possible effects of too-little boron:

“stunting and distortion of the growing tip”
“brittle foliage and yellowing of lower leaf tips”
reduced flowering
reduced fruiting
distorted fruit
“brown heart” (mushy brown centers) in root crops like turnips and rutabagas
hollow stems in broccoli and cauliflower
brown or otherwise discolored curds on cauliflower

Kelling’s Soil and Applied Boron publication adds that cabbages that are low on boron may show an “internal breakdown of head”.

Which plants need the most boron?

Some vegetable crops need more boron than others.

Broccoli growing in the organic home garden.

Ron Goldy’s U Michigan publication lists crops and their relative need for boron. The high-need vegetables for boron he includes are these:

broccoli
cauliflower
celery
table beets
turnips

How can I provide boron to my garden?

One way to add boron is to follow the instructions on the UGA soil test report, to mix a tablespoon of borax in water or with soil and to spread that across a 100-foot row of garden, especially in areas where higher-need vegetables are growing. If your garden is not in rows, or is smaller, it will need less borax.

The borax you will need is in the laundry section of your grocery store, in the box of 20 Mule Team Borax. This should be fine for organic gardens, because it is a mined mineral.

You will need to be careful with this product, though, because it is easy to use too much. Do not apply the boron every year without having the boron levels tested at a reliable soil lab.

If you prefer to use another product, one that contains many micronutrients, including boron, to safely fill any gaps, try kelp meal. It is much more difficult to use too much boron when using kelp meal, because it is a much less concentrated source of the micronutrient. There is enough, though, to help your plants. Just follow package directions for safe use in your organic home garden.

Georgia isn’t the only state with low-boron soils

The 20 Mule Team Borax company notes that boron will be at low levels in soils that are sandy, or acidic, or that are low in organic matter (like Georgia clay!), or that are in areas of high humidity.

The company has found that low-boron levels are a common problem in soils east of the Rockies and in the Pacific Northwest. The middle of the country and the Southwestern region mostly have sufficient boron.

To learn more about soil fertility in organic home gardens, read my posts about potassium sources, soil pH, building good garden soil, and side-dressing your garden crops.

GGIA Trade Show Notes for Organic Gardeners

29 January, 2019 by amygwh 6 Comments

The trade show at this year’s WinterGreen conference of the Georgia Green Industry Association (GGIA) provided a look at some new (and not so new) products and plants for organic gardeners. The event was held last week, in Duluth, GA.

Most vendors at the trade show specialized in ornamental (non-edible) plants, machinery for large operations, products for commercial nurseries, and chemical-companies, but I located some local/sustainable/organic-related vendors, to share with you.

Recycled plastic nursery pots

East Jordan Plastics, in Michigan, displayed planting trays, growing pots, and some larger containers made from recycled plastics. Many gardeners are concerned about the excessive use of plastics in gardening. It is good to know of a plant-product company that is working to cut back on plastic waste, by re-using containers and recycling other plastics to create new containers.

RootMaker pots

Image from the RootMaker catalog showing difference in root growth between sprout in regular pot versus sprout in RootMaker pot. — Image from RootMaker catalog.

RootMaker trays and pots for growing plants are the result of research in container design, with the goal of more robust root systems. The trays and containers that I examined seemed very sturdy — like they would last for years — and the informational literature was very compelling. The pots and trays have an unusual pattern of protrusions and holes inside, and those, according to the information, guide root growth into more-branched root systems.

I will be trying a RootMaker tray this year. The representative at the Trade Show did give me a couple of fabric liners, for use when growing plants in cinderblocks, so I cannot say that I am 100% unbiased. I will have to buy the tray, though.

Rice hulls for mulch

Until this trade show, I had not heard of using rice hulls as mulch in containers or as a substitute for perlite in planting mixes.

PBH brought samples of parboiled rice hulls, so people could see the actual product and understand how it can be used. The rice hulls are approved for use in organic systems. I did not bring home a little baggie of rice hulls, but I could have. There were plenty on the table. I did bring home the informational literature, to learn more.

Rice hulls pictured on the cover of an article titled "Rice Hulls 101".

PBH Nature’s Media Amendment is from Riceland Foods. This shouldn’t have been a surprise, but it was. It makes sense that the rice industry would want to find a good use for this bi-product of rice production. Looks like they were successful.

Pope’s CBD oil

This isn’t organic and it isn’t about growing, but I did learn that Tennessee grows industrial hemp. The CBD oil was displayed in what was otherwise an all-succulent-plants booth, for Pope’s Plant Farm. CBD oil seems to be a popular product these days. If anyone was looking for a local (-ish) source of CBD oil, Pope’s Plant Farm is one place to try.

Display for Pope's Plant Farm at the 2019 GGIA Wintergreen Conference.

The little succulent plants in the Pope’s booth were very cute. If I were more of an indoor gardener, I would probably grow some. My oldest son in Colorado does grow little succulent plants, so I pay more attention to them than I used to.

Bottom’s Nursery for fruit trees and other plants

Its plants are not organically grown, but after they are planted, most of the varieties at Bottoms Nursery will not need intensive programs of chemical sprays. All the varieties I saw in the catalog are relatively easy-care fruits that would do well when switched to organic management after planting, even in the South. Some are varieties that would do well in small space gardens.

Front cover of the 2019 catalog for Bottoms Nursery, which is in Concord, GA.

The fruit trees at the back of the booth are what attracted my attention. The first tagged tree I noticed was a Kieffer pear, which I know to be both hardy and a producer of good-tasting fruit.

I wasn’t the only person drawn to the booth of Bottoms Nursery. Another vendor was there, discussing trees and other plants to order, to sell in his General Supply store.

General Supply, Inc, in Blairseville, GA

General Supply is the kind of “everything” store that makes some gardeners go into raptures. This is the store mentioned above that will be selling plants from Bottoms Nursery, but it is also a source of tools, pet supplies, small farm supplies, and a million more interesting things.

Hand tools display in General Supply booth at GGIA 2019 Wintergreen Conference.

Of course, hand-tools are pretty appealing for gardeners working in small space gardens. We don’t need a large assortment of full-sized equipment for our little plots, but good tools make the work easier.

I was especially interested in the Truper brand tools (long-reach 15″ length, ash wood handles, sturdy forged “business ends”), but a full line of Corona tools — which are long-lasting and easy to use — was also on display.

The guy at the booth (so sorry that I did not record his name!) and I discussed the ergonomic benefit of tools that have the “business end” at a right-angle to the handle, when he showed me another tool designed for easier use.

The pruner on the right, in the nearby image of two Corona-brand pruners, has a different angle for the cutting edges. Do you see the difference? According to the guy in the booth, the angled pruner on the right would be easier to use on some branches, because it allows your arm and wrist to stay aligned, rather than to bend.

I haven’t tried it, so I don’t whether that really works, but I would be interested to try. When late-winter pruning time comes around (soon!), it would be good to avoid aggravating old injuries.

Gardeners heading toward the Blairesville area might want to put this store on their list of places-to-visit.

What else happens at the GGIA WinterGreen conference?

In addition to the trade show, the event provides continuing education opportunities for commercial lawn and garden folks. I did attend a workshop about Beneficial Insects, but that story is for another post.

Soil pH and Garden Success

15 December, 2018 by amygwh Leave a Comment

When a garden hasn’t been doing well, one of the first conditions to check is the soil’s pH, its acid-alkaline balance. The pH scale goes from 0 to 14; 7 is the neutral pH, measurements below 7 are acidic, and measurements above 7 are alkaline.

For reference, distilled salad vinegar has a pH in the range of 2 to 2.5 (acidic), and cold-process soap has a pH in the range of 9 to 10 (alkaline).

Soil pH influences how well plants can take in nutrients from the soil, so getting a garden’s soil into the best pH range for your plants will help them be healthier and more productive.

What is less well-known is that correcting a pH that is either too high or too low takes time. Testing soil pH should be done now, or soon, for gardens that have not done well in the past year.

What pH is good for gardens?

Blueberries will be ripe beginning in mid-to-late June. — Blueberry plants prefer a soil pH near 5.

Most garden veggies need a soil pH of between 6 and 7. Where I live, northwest of Atlanta, the natural soil pH is lower than that range — it is naturally acidic. With that acidity in mind, many people here routinely add lime to their lawns and gardens without checking the soil pH first, and end up with a soil pH that is too high.

When I worked at the local Extension office and managed the soil samples that went to the soil lab at University of Georgia (UGA), it was not unusual to see some samples with soil pH around 5, but others with pH higher than 8. Those higher pH soil samples were from lawns and gardens that had been limed pretty much every year.

Once, a friend who decided to plant blueberries in the space where she had originally kept a vegetable garden sent a soil sample in to the lab at UGA. The lab found that the pH of her soil was 7. This pH level was not a surprise because she had been spreading ashes from her fireplace on the garden. Wood ashes are a good source of potassium, but they raise the soil pH.

For many veggies, a soil pH of 7 is fine, but the blueberries she hoped to plant in that space prefer a pH closer to 5. That soil needed some work before it would make a good home for blueberries.

How can I find the pH of my garden soil?

Example of easy to use soil pH test kit for home gardeners.

The most reliable method of finding your garden’s soil pH is to send a soil sample to your state’s soil lab. Call your local county Cooperative Extension office to find out how to take a representative soil sample, how to package it, and the lab fee for this service.

Another option is to purchase a pH test kit at a local garden center. One I have used (pictured nearby) includes a container with color chart for comparison, capsules of pH-indicator-powder to add to the container, and instructions.

The basic instructions for this kit, and others:

put a tiny bit of garden soil into the container
add the indicator powder
add water up to a line near the top
put the lid back on the container, then
mix the parts together by shaking the container until color develops.

You find the pH by comparing the color of your sample to the chart on the front of the container.

Soil sample in pH test kit with water and indicator powder, to read the soil pH. — Sample in pH test kit shows pH of soil in my upper flower bed to be about 6.5.

How to lower a too-high soil pH

The UGA soil lab sent information to my friend about how much aluminum sulfate (the cheapest option) to add in order to bring the pH down to a better level for blueberries. If you know that the pH of your garden soil is too high, but don’t have a lab-recommendation for how to lower it, the amount of elemental sulfur (my preferred option) needed can also be found in a table by Clemson University Extension, in its Changing the pH of your soil publication.

For a soil pH that is only slightly high (about 0.5 higher than the desired level for your plants), one of my county’s former Extension agents used to recommend mixing sphagnum peat into the soil as a quick fix. Iowa State University Extension suggests other amendments that can lower a too-high pH, including “elemental sulfur, aluminum sulfate, iron sulfate, acidifying nitrogen, and organic mulches.”

There is a note, too, that a very high pH (over 8) is hard to bring down. When the local Plant-a-Row-for-the-Hungry garden (one of my volunteer groups/projects) was at a location that had a high-pH soil, we added the recommended amount of sulfur several years in a row before the pH started to come down.

How to raise a too-low soil pH

The Iowa State University publication How to change your soil’s pH includes a table showing how much ground limestone will be needed to raise soil pH. If you have hydrated lime handy, and think it might be a “quicker fix” for a too-low pH, please don’t try it. The risk of raising the pH too high with this product, by accident, is large. Lowering the pH after over-liming is difficult and can take a long time. Use ground limestone instead of quick lime or hydrated lime.

It takes more lime to raise pH in a clay soil than in a sandy soil. In general, according to the table in the Iowa State publication, for 100 square feet of clay-soil garden, it takes 5 to 6 pounds of limestone mixed into the top six inches of soil to raise the pH by 0.5.

When is the best time to adjust the soil pH?

For my friend’s blueberries, the UGA lab report recommended that the bushes shouldn’t be planted until 6 months after applying the sulfur. If she added the sulfur in October, that means blueberry-planting should — for best effect — wait until April. That is pushing the boundary for good planting time for woody plants like blueberries; as spring progresses and the weather warms, newly planted bushes are less likely to do well. They need time in the soil for their root systems to become established before being stressed by the heat of a Georgia summer.

What this means is that soil testing should be done now, if it hasn’t already been done, so adjustments to pH can be made soon enough to benefit plants that will be planted in spring.

What soil pH is best for my plants?

An article by Lewis Hill, published in Robert Rodale’s The Best Gardening Ideas I Know (1983) includes a list of some garden plants and the pH ranges they prefer. I’ve pulled some of the food plants from his list to post here:

pH 4 to 5: blueberry
pH 5 to 5.75: blackberry, grape, parsnip, plum, potato, pumpkin
pH 5.75 to 6.5: bean, citrus fruits, cowpeas, currants, gooseberry, oats, pepper, rutabaga, rye, squash, strawberry, tomato, turnip
pH 6.5 to 7: apple, beet, broccoli, buckwheat, butternut, chicory, chives, cucumber, eggplant, endive, kale, leek, muskmelon, onion, pea, peach, radish, raspberry, rhubarb, spinach, watermelon, wheat
pH 7 to 7.5: alfalfa, asparagus, barley, cabbage, carrot, cauliflower, celery, lettuce, nasturtium, parsley

This list may help other gardeners in planning what to plant where, but it is comforting to remember that plants will still grow and produce in soil that is slightly outside their preferred pH range.

This is lucky, since most of us grow many of these plants mixed all together in our gardens. However, for peak production, planting in soil that is actually the preferred pH for each crop works best.

Succession planting with preferred pH for each crop in mind

When I plant Irish-type potatoes in the spring, I will have added some sphagnum peat to their soil to bring the pH down a bit, but not all the way down to 5. Knowing the pH preferences of other crops helps me know what to plant after the potatoes in that space. For example, cabbages in that space would likely be a total bust, because their pH preference is so much higher (7 to 7.5!).

After potatoes are harvested, a better option than cabbages would be to let a nearby vining crop, like melons, sprawl across that space. Another option would be to plant a crop there that prefers a lower pH range, like beans or cowpeas that thrive at pH 5.75-6.5.

(If this information seems helpful or interesting, please remember to “like” or “share” it. Thank you!)

Something is Making Holes in My Squash Flowers and Stems

11 September, 2018 by amygwh Leave a Comment

Over the past couple of days, I have noticed that several flower buds on my zucchini squash plants don’t look healthy. The flower buds have stayed small and turned pale and droopy. Today, I finally took the time to REALLY inspect my plants. What I saw is a lot of bad news.

The holes in the flower buds and the holes in the stems could — possibly — be caused by several kinds of insects. However, the piles of pale green, round globs like tapioca, and the yellow globs too, are most likely frass (poo) from caterpillars.

Around here, a major cause of this kind of damage is squash vine borers. The adult moths lay eggs on the plants. Then, the tiny caterpillars that hatch out of the eggs eat their way inside the plant, where they eat and eat until they have killed the plant from the inside.

I pulled up two of my five zucchini plants to try to find the culprits/caterpillars. As I dissected the plants, this is what I found:

What are pickleworms?

Pickleworms, the caterpillars of a night-flying moth, are a common summertime pest in the South. They are pests I have seen before, but I have not seen such extensive damage to plants from their activity before. Who knew that they would gnaw right into a stem? Not me. At least, not until now.

If the damage had been from squash vine borers, I would have pulled up all five of the zucchini plants and called them an interesting late-summer experiment that I never need to repeat. Since the damage is from pickleworms, I am trying another option. That second option is the use of an organic-approved product for caterpillars.

Organic control for pickleworms

I have mixed up some “Bt for caterpillars” – the product at my house is Thuricide, but others are available – and I’ve sprayed it all over the stems and flower buds of the remaining zucchini plants and my little patch of cucumbers. The name “pickleworm”, if you haven’t already guessed, alludes to a fondness for cucumbers. Since I like cucumbers, too, it would be nice to bring any cucumbers that these plants make into my kitchen, without caterpillars inside.

I planted seeds for cucumbers the same day I planted the zucchini. With a time-to-maturity of 65 days, they seemed less likely than the zucchini to make a crop before the first frost, but they are another late-summer garden experiment. Since they have plenty of flowers on them, the odds look good that I might harvest a couple of cucumbers before the end of October.

This hope for cucumbers depends on me and the Bt. It will need to be re-applied every week, and after every rain, for the Bt to work well.

Wish me luck?

Beneficial Garden Insects: Flower Flies

31 July, 2018 by amygwh 1 Comment

While I’ve been walking outside our little town in Italy, missing my vegetable garden, I have paid attention to the local plants. On good days, I see a lot of flowers and pollinator-insects. At first, I thought the pollinators were all bees. Then, I looked closer. Many of them are actually flower flies, a different group of beneficial garden insects.

Flower flies, which are beneficial garden insects, look like bees but without the sting. — Flower flies are beneficial garden insects.

What are flower flies?

Flower flies really are flies, but a lot of them look like bees. It is possible that looking like a bee prevents some predators from eating them. I don’t know if that mimicry really works, though. We used to have a dog that ate carpenter bees when she could catch them. The stinging inside her mouth didn’t seem to stop her from catching and eating more.

Flower flies do not sting or bite, but they do eat nectar and/or pollen as adults. As they visit flowers to gather food, they pollinate the flowers. Flower fly babies (larvae) eat aphids and other small insects. These are definitely beneficial garden insects!

Organic gardens, in particular, rely on pollinators and predators in the garden to increase harvests and reduce pest problems. We can wait for our helpful predators (like flower flies, wasps and ladybugs) to eat the aphids, no spraying required!

Flower flies are also known as syrphid flies and as hover flies.

How can I tell which is a flower fly and which is a bee?

With only a brief glance, it is not easy to tell bees and flower flies apart. If you have the fortitude (and lack of bee-allergies) that allows you to look a little longer, you might see the difference.

Check the antennae

Flower flies have short, straight, stubby antennae. The antennae may be so short that they are hard to see. Bees have longer antennae, and their antennae are more likely to bend.

Check the wings

All flies have only two wings (one pair), and you can easily see them. One wing is on each side of the body.

Bees have fours wings (two pairs). The larger front pair of wings is easy to see, but the hind-wings can be hidden below the front pair. You might not be able to see that there are four wings.

Check the eyes

Eyes of flower flies are larger, and more on the front of their heads. Bee eyes are shifted a little to the sides of their heads.

Check the back legs

Flies do not collect pollen in clumps on their back legs. Some kinds of bees, especially our native, solitary bees, also do not collect and carry pollen on their back legs.

However, bumble bees and honeybees often store clumps of pollen on their back legs, to carry back to their colonies. If you see a bee-like insect that has pads of orange, or red, or yellow on its back legs, that is a good sign that the insect is some kind of bumble bee or a honeybee.

How can I attract flower flies to my garden?

University of California has published an easy-to-use table of plants that attract flower flies (see page 16). The table is deep within a document that is not super-easy to read, and not all the plants will grow well in the Southeastern US, but many will.

Here is a short list of plants that are known to attract and/or support flower flies to your organic garden, that I know will grow in the Southeastern US:

buckwheat, coriander/cilantro, thyme, Italian oregano, sweet alyssum, fennel, tansy, white-flowered yarrow

Side-Dress Your Vegetable Garden if Needed

2 July, 2018 by amygwh Leave a Comment

If plant growth in your garden has slowed, or your plants are looking puny, it might be time to side-dress your vegetable garden with fertilizer. What does that mean? Side dressing is applying additional fertilizer near your crop plants, either spread on the ground around them or in a little furrow a few inches away.

Side-dressing helps some crops more than others

Some crops will not need additional fertilizer in mid-summer to make a full harvest. These, mostly, are the beans and peas — Southern peas especially, like purple hull peas and zipper creams. Most of the other fruiting crops in a summer garden, like tomatoes, peppers, cucumbers, corn, eggplants, and squashes, may benefit from additional fertilizer. These crops are often referred to as medium feeders or heavy feeders. They have a higher need for some nutrients.

Side dress your vegetable garden tomatoes in mid-summer, if needed. PHOTO/Amygwh

For plants that benefit from additional fertilizer in mid-summer, it usually is applied either when plants have begun to set their fruit (squash and cucumbers count as fruit, since they have seeds), or, for corn, when it is “knee high.” If your crops are further along than this, it is not too late to side-dress, if plant growth or productivity seems slow.

How to know if you need to side-dress your vegetable garden

These gardens are most likely to benefit from mid-summer side-dressing with fertilizer:

Gardens with sandy or fast-draining soil
Gardens that have received more than the usual amount of rain
Gardens fertilized with water-soluble, conventional, chemical fertilizers
Gardens that support a lot of medium and heavy feeders

In the first three examples, some of the nutrients added in spring may have washed away, out of reach of the plant roots. When nutrients are out of reach, plant growth will slow down, some plants may start to look a little pale, and harvests will not be as large as they should.

If the only plants in your garden that look pale/puny by mid-summer are the tomatoes, peppers, and/or eggplants, and all other crops are growing well, these crops might need a little extra magnesium. In my county, soils are low on magnesium. The tomato-family plants all have a slightly higher need for magnesium than other crops. This combination can result in plants that are pale and less productive.

To boost the available magnesium for these plants, use epsom salts. Dissolve a couple of tablespoons of epsom salts in two gallons of water, and pour it on the ground around your plants. Two tablespoons-full dissolved in two gallons of water should be enough for four plants. If the plants start to look darker green in about a week, then they needed the magnesium.

You also, of course, could get your soil tested through your local County Extension office. A soil lab report will tell you whether any nutrients are in short supply and offer a fertilizer recommendation. Extension fertilizer recommendations are, at this point, still all for conventional, chemical fertilizers, but even this can be helpful in pointing out the needs of your garden’s soil.

Some gardens may not need side-dressing

Gardens with soil that is, essentially, all compost
Gardens that are 100% beans and Southern peas that have been inoculated with bacteria that help fix nitrogen

If your garden soil is all-compost in a raised bed, and the compost was all new this spring, then the odds are good that your plants will not need side-dressing. Some community gardens in my county fill new beds with a product called “Soil3”, from SuperSod. This is an all-compost product. Soil3 and similar composts available in other areas can provide all the nutrients the garden plants will need for the first summer. Organic fertilizers may be needed in increasing amounts in later years.

Which organic fertilizer is good for side-dressing?

The vegetable garden fertilizer you already have
Fish emulsion or a seed-meal-based fertilizer
Worm compost, yard compost, compost tea

If you have a complete garden fertilizer already, one that you used in spring, use that again in mid-summer, following directions on the container.

However, the nutrient that is most often in short-supply by mid-summer is nitrogen. It can leave your soil by going into the air in addition to being washed away. If you can locate a higher nitrogen fertilizer product like the Alaska fish emulsion fertilizer or the seed-meal-based Nature’s Source Garden Plant Food, those can be good choices.

Composts are also good choices. To side-dress with these, be sure to rake them in — shallowly to avoid damaging roots — around the plants, covering it all with soil. Then water the compost in well to give the soil bacteria, fungi, and other small life-forms better access, to start breaking it down for use by plants. Use a big shovelful of yard compost, or a cup or two of worm compost, per plant. Worm compost is usually a more concentrated source of nutrients than yard compost.

If you make compost tea from your compost, to pour around your plants, root-damage becomes a non-problem. The tea may need to be poured around the plants more often than just once in mid-summer, for best effect. Compost tea applied to leaves can also slow down the growth of fungal leaf diseases. (Compost tea recipe is in the “treating mildews” section of the Summer Squash blog post.)

For gardens prone to leaf disease problems (pretty much every garden I have ever seen), regular use of compost tea can be helpful in extending harvests of some sensitive crops, like cucumbers and tomatoes, further into the summer.

Any gardener who has a small garden, but no compost pile or worm bin at home, might be interested in trying the compost tea bags. Sustane Compost Tea Bags are convenient, and no straining is required. I have used these to make tea for my own garden, and they seem helpful. When pressed for time, it is nice to not have to strain the compost bits out of the tea before filling a spray bottle.

Summer Squash in the Southern Garden

11 June, 2018 by amygwh 1 Comment

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.

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

Striped Caterpillars in the Garden, Eating the Dill

12 May, 2018 by amygwh Leave a Comment

Several weeks ago, while I was working in the garden, a battered, tattered black swallowtail butterfly flitted into my dill patch. While she was there she laid some eggs. Eventually, some of those eggs hatched, and then there were caterpillars in the garden, eating the dill.

They ate and ate. After awhile, some of the caterpillars disappeared. I assume other wildlife, such as birds, ate them. The last time I saw them, a few days ago, there were three left, fat and striped and still eating the dill.

Caterpillars in the garden are not always a problem. This one will be a black swallowtail butterfly. — PHOTO/Amygwh

They have all gone now, which means I can finally harvest the dill. The plan is to dehydrate most of it, for use this winter. I am thinking of using it on fish, in particular. It is also good in spanakopita, but I don’t eat cheese like I used to, even feta, so that recipe is no longer “in the rotation”.

What to do about caterpillars in the garden?

Even if these striped caterpillars were more voracious eaters, gnawing my dill plants down to little nubs, I probably would just make a note to plant a lot more next year. Accepting some insect-damage is part of the organic gardening way.

In addition, the world has been losing pollinators over at least the past couple of decades, probably longer. Even though butterflies are not our most effective pollinators, removing these with either an organic pesticide or a mechanical method like smashing would not be good for the future of food in the world.

Luckily, the caterpillars have left plenty of dill for us humans.

When other caterpillars in the garden eat so much that a plant is nearly bare of leaves, then control measures may be desired. As usual, the first would be to keep the adults, the butterflies, away from the plants completely. Draping small-meshed netting or a spun row cover on a support structure over the plants can keep adult fliers away (see post about cabbage butterflies and moths).

What else do these caterpillars eat?

These caterpillars are sometimes called parsley worms, because they eat many plants that are in the parsley family. If you guessed that one of those plants is parsley, you are right! Fennel and carrots are other garden plants in the same family, as is dill.

University of Florida has published a fact sheet about the Eastern black swallowtail butterfly, its lifecycle and ecology. The fact sheet includes a list of other plants these caterpillars will eat. Some are native plants, like mock bishop weed and water hemlock. Some are not native across the entire U.S., but have been introduced. One that many people will recognize is Queen Ann’s lace.

Where did the caterpillars go?

Surprisingly, Joe and I found a chrysalis way across the yard, in a flower bed, on Thursday. I almost never find these, so this one made my day.

Chrysalis of black swallowtail butterfly from 10May2018, in Georgia. PHOTO/Amygwh

The chrysalis is on a leaf of a hardy amaryllis, given to me by my mother-in-law many years ago.

Which beautiful pollinators are in your garden?

Small Garden in Early Spring

7 April, 2018 by amygwh 2 Comments

My small organic vegetable garden is providing greens right now. Kale and spinach are growing together in a half-barrel in the front yard. I started these indoors, from seeds, while it was still winter. Before moving them outside permanently, I used one of those warmer weeks in February to harden them off. By “harden them off”, I mean that I moved them into a dappled sun area for a few hours while it was warm. Each day, the plants spent a little more time outside. After six days of this transition-time, I set the small plants into their current positions in the half-barrel planter.

Half-barrel planted with kale and spinach, organically grown. — Winter-planted kale and spinach produce plenty of greens in early spring. PHOTO/Amy Whitney

In this little greens-garden, three kale plants are clustered near the center, and nine spinach plants are set, evenly spaced, in a big ring near the outer edge.

These container-greens, along with the rocket that is still growing with cilantro in another large container, add variety in texture and flavor to lettuce-based salads.

The kale is producing enough leaves that some can also go into a white-bean soup in a few days, with plenty left for other purposes (shepherd’s pie, pizza toppings, salad, etc.).

Organically grown garlic, planted in fall, as seen in spring. — Intensively-planted garlic grows throughout the winter, making a small forest of garlic. PHOTO/Amy Whitney

Also in the garden, the garlic, which was spaced in a grid-pattern at planting time, resembles a little forest.

This was planted back in early winter (I missed the recommended October planting time for my area). The stems rising out of the ground look thick enough to make decent-sized bulbs, so maybe the late planting won’t hurt the harvest too much.

Garlic, shallots, and onions all benefit from a little extra fertilizer as they start making their bulbs (now, in my garden), so I am applying fish emulsion fertilizer (the 2-3-1 version), mixed with water in my watering can, every 7-10 days.

My onions are not bulbing onions — I planted the bunching type this year — but the extra fertilizer helps them, too, to make more little onions.

Fall Garden Planning guide for vegetables in the Southeastern US. — A guide to choosing and growing crops and setting a planting schedule **that will work** for a fall garden in the Southeastern US.

Also — my biggest news — my little book on Fall Garden Planning is nearing completion! I should be receiving a couple of “proof” copies this week. If all looks good, the book will be available within a few weeks.

Writing it, and learning all the technology bits to get it published, has been a grand adventure! I have been lucky, too, to have some very tolerant/patient friends who read an early version of the text and said nice things about it even though it had a long way to go.

Best wishes for great gardens!