Hoverflies are beneficial insects

As mentioned in an earlier post on this blog, I planted a fairly large plot of buckwheat adjacent to our vegetable garden this spring. The main idea behind planting buckwheat was to provide forage primarily for honeybees and for any other pollinators that might be around to take advantage of it.

As it turns out honeybees are in the minority. When surveying the buckwheat plot, I noticed for every one honeybee I saw there were ten or twenty other pollinators. They included butterflies, small wild bees, small wasps, many kinds of beetles, flies and hoverflies.

Hoverflies are especially good to have in the garden. The adult hoverfly is a very agile flyer able to hover in one spot then zoom away, stop on a dime and hover in place again — they can even fly backwards.  They don’t have teeth or mandibles so they can’t chew or tear into things. Their mouth parts are spongy and are designed to soak up nectar and other liquids as well as picking up small particles such as pollen. That is why they’re so attracted to the buckwheat flowers.

Hoverflies have a superficial resemblance to bees.
Hoverflies have a superficial resemblance to bees.

Hoverfly larvae on the other hand are insectivores that eat small soft-bodied insects. In the garden that means mostly aphids, thrips, leafhoppers and scale. All four of these common garden pests have a stage in their lifecycle when they are soft-bodied.

After mating the adult female hoverfly buzzes around looking for a likely spot to lay her eggs, someplace where her young will have easy access to food. How does she know where the best spot is? Aphids and those other insects get all their nutrition from plant juices. They can only use part of the sugar in plant sap so they excrete the unneeded sugar as a syrupy liquid called “honeydew”. It’s the honeydew that attracts the female hoverfly: where there’s honeydew, there are insects for her young to feed on.

During the larval stage, each individual hoverfly will eat up to 400 aphids and other insects giving it the needed protein to go on to further development.

Since they are such good flyers, it’s very easy for female hoverflies to fly from the buckwheat to our vegetable garden and back again. The habitat that buckwheat provides enables the beneficial insect population to grow much larger than it would otherwise. That is a good lesson about the advantages of encouraging beneficial insects with plants instead of trying to maintain a garden in the middle of a sterile environment like a mowed lawn.

Bob

 

Planting buckwheat for weed control and helping honeybees

I have an area in the garden that I will not be able to plant this year. Instead of letting it stay fallow and grow weeds, I planted buckwheat. It’s something I’ve done through the years whenever I’ve been unable to use an area for one reason or another.

Buckwheat is a fast growing plant that will out compete most weeds. Planting buckwheat allows me to place-hold that unused garden area while reducing weeds at the same time. It also takes up mineral nutrients from that soil that are unavailable to other plants. Those minerals are incorporated into the growing plant. Eventually, I’ll cut down the buckwheat and till it into the soil. As it decomposes, all those minerals will be released back into the soil in a form that other plants can use.

Buckwheat is not an actual wheat at all. Wheat is a type of cultivated grass, buckwheat on the other hand, is a broad-leaf plant.  While regular wheat forms inconspicuous flowers that are hidden, buckwheat grows a profusion of while flowers. Those flowers are very attractive to honeybees and other pollinators. The dark, strong flavored honey that results from buckwheat nectar is highly prized by some honey aficionados.

Many years ago when I first started beekeeping, that dark buckwheat honey was considered a low quality product. Now that has all changed and buckwheat honey is often sold at a premium.

Buckwheat seeds have a distinctive pyramid shape.

Planting buckwheat is a simple process. Till the spot you’re planting, spread some seed over the area and lightly rake it into the soil. Figure on using a couple pounds of seed per thousand square feet. In a few days you’ll see the young buckwheat plants emerge from the soil. If after a week or so of growing, some of your planting looks a little thin, sow more seed to fill in the area. Buckwheat can cover a space up to ten inches in diameter but an open spot larger that a foot across will allow weeds to grow.

I’ll keep you updated on the progress the buckwheat makes through the growing season.

Bob

Winter rye cover crop tilled into garden soil

The rye cover crop I planted last fall made tremendous growth this spring. The plan all along was to till it into the soil before planting a week or so before planting.

Timing is important when it comes to tilling under a cover crop like rye. The plants grew and entered the “boot stage” of growth, forming flower/seed heads inside the stalk. This is the ideal time to till rye into the soil. At that stage the plants are about 20-24 inches tall.

 

At mid-May, the rye was nearly two feet tall
At the boot stage you can feel flower/seed head forming inside the stalk.

I thought the garden was quite fertile, and it is, but the spots that received a little heavier application of compost last fall are much greener, taller and are developing seed heads earlier. It’s a good demonstration about the benefits of compost.

The plants were too tall for the rototiller to handle on its own. I had a couple of options, either kill the rye with an herbicide like Roundup, which is what most of the conventional farmers do, or mow it. Since I’m trying to keep it an organic garden, I mowed.

Twenty inches tall sounds like a lot for a mower to handle but rye is very tender and juicy in the boot stage — they are almost all water. If I had mowed it before the boot stage, the plants would have grown back just like a lawn. If I waited too much longer, the plants would have been tougher and drier as they begin to form seeds. That would have made it much more difficult to till and would leave too much coarse plant material in the soil.

The chopped up rye dried and left a fine textured residue that was very easy to till.

Plant growth stage was not the only thing I was checking, I looked at soil moisture too. All the rain we had at that time left the soil temporarily saturated but it dried fairly quickly.  Tilling a garden that is too wet destroys its soil structure negating most of the benefits that a cover crop provides. The rye along with winter freezing and thawing improved the soil structure by forming loose aggregates of soil particles leaving plenty of space for roots to grow.

The rototiller easily handled the rye at this point.

Another very visible advantage to this cover crop was the lack of weeds this spring. By this time the garden would have been full of all kinds of broad leaf weeds and grasses. Dandelions would have come and gone by now. The rye did its job and out-competed virtually all other plants giving me a head start over the weeds this year.

Bob

 

 

 

Winter cover crop update

We’ve all heard that old expression, ” It’s like watching grass grow”. We’ll that’s kind of what this blog post is about. No, wait, that’s exactly what this post is about. Not to worry though, I’ve done all the boring work for you by watching that grass grow. So there’s no need to click away from here yet.

The grass I’m talking about is the rye I planted in the garden last fall as a cover crop. If you don’t know what I’m talking about, go back a few pages in this blog and  you’ll find a couple of posts about it.

Just by looking at the rye, not much has changed visually except much of it was grazed by geese, rabbits and other small animals. That won’t hurt it though. It’s not as bad as animals grazing on your lettuce for example.

Winter rye provides a source of winter food for wildlife.
Winter rye provides a source of winter food for wildlife.

Although you can’t see it, the rye has undergone a major transformation. Because of the effects of the cold winter temperatures, the plants have experienced a process called “vernalization”. This cold period radically changes the internal processes of the plants enabling them complete their lifecycle by growing flowers and eventually forming seeds.

Without those several days of freezing temperatures, rye plants would not be able to reproduce. Other cereal crops like winter wheat and winter barley require similar vernalization. Oats on the other hand are not winter hardy therefore don’t require vernalization to form seeds.

I had a discussion with a soil conservation technician last fall. He mentioned this was one of the few times he’s come across a garden with a winter cover crop. Maybe he has not been looking in the right places, I’m sure many readers of this blog use cover crops in their gardens. You’re welcome to share your cover crop experiences with other readers in the comment section below

To me watching grass grow is not boring at all — watching paint dry, well, that’s a whole different story.

Bob

Fall rye cover crop growth progress in the garden

Our mild autumn temperatures have accelerated the growth of fall-planted, over-wintering, cover crops.

Back in October I wrote about planting cereal rye as a cover crop in my garden. Since then the crop has germinated and made excellent progress toward establishing itself.

When rye seed germinates, it emerges out of the soil as a single shoot. As time goes by and temperatures are conducive to plant growth, leaves begin to form on the main shoot.

This picture was taken at the end of November. The rye is a bout 3-4 inches tall.
This picture was taken at the end of November. The rye is about 3-4 inches tall.

After a couple of weeks of growth, the plant enters the “tillering” stage of development.

Rye is a bunch grass, a self-descriptive term meaning that the plant grows in tuffs or bunches instead of spreading by over-the-ground stems called rhizomes. To spread and take advantage of growing space, the bunch grasses form extra stems called tillers. Tillers grow from the main stem of the plant.

When you look at a rye plants and see it staring to form dense tuffs, that growth you see is the tillers. Each tiller has the ability to form it own roots. In that way the plant has the ability spread vegetatively, essentially producing baby plants along side the main plant.

Farmers are concerned about encouraging tillering because the more fully-developed tillers the crop has, the greater the yield.

Extra tillering allows the plants to fill in bare areas thereby compensating for thin stands or weak germination.

My rye is is in the early stage of tillering and should be in fine shape going into the winter.

Bob

Rye as a cover crop in the garden

I closed the garden down during the third week of October this year hoping that the weather would stay mild so my cover crop of rye would germinate and make some good growth before winter sets in.

Rye is one of the best winter cover crops for our area. You can let your garden grow for a full season and still have time to plant your cover crop after the garden has stopped producing. Fall-planted rye will make good growth and do very nicely over winter, especially if we have a covering of snow to protect the plants from harsh winter winds.

On sloping sites, cover crops such as rye, stabilize the soil keeping it from washing downhill. On flat sites, cover crops keep wind from blowing away your hard-earned topsoil.

It’s true, you can just leave those small fall growing weeds in your garden and they will do much to control erosion but rye has another huge advantage.  A cover crop of rye will reduce the bio-mass of weeds by 80-90% vs an area with no cover crop. Because it grows so fast in the fall, rye will smother weeds that are trying to grow. Not only that, its roots produce a compound that keeps weed seeds from sprouting. Compare that to a garden that is covered with small over-wintering weeds waiting to grow again in the spring and you’ll see what an advantage that is.

 You can’t actually see it with your eyes but soil nutrients can get washed down into the soil profile by autumn rains and melting snow far enough where it is no longer available to your garden plants. As it grows, rye will capture soil nutrients retaining them in the form of roots, leaves and stems.

Another fascinating thing about rye is that it has the ability, unlike many other plants,  to extract usable minerals directly from raw soil particles. It then uses the minerals for its growth and development — essentially making its own fertilizer. In the spring, the rye plants are tilled into the soil. As they decompose, these new minerals are released into the soil for garden plants to use.

This about how for apart the seeds were after I broadcast them.
This about how for apart the seeds were after I broadcast them.

I prepare my garden for its cover crop by first removing much of the existing plant material, mostly the stuff that tends to get caught up in the tiller tines. Then I’ll run the tiller over the garden to mix in the plant debris. At that point the area is ready for seeding. I evenly broadcast about three pounds of rye seed per thousand square feet evenly over the area. Then I make a very shallow pass with the tiller to mix the seed into the top couple of inches and I’m done.

Keep in mind you are not planting a lawn here. Too much seed will give you a dense rye plant population making it very difficult to till under your rye crop in the spring.

Bob

Plant oats as a garden cover crop

It’s not your imagination, the growing season is winding down early this year. The excessive rain and cooler than normal temperatures in our area have combined to make it a challenging season for many garden plants especially the warm weather crops like tomatoes or peppers.

Farmers are noticing it too. Many field crops never fully recovered from poor start of the season and are showing signs of maturing early. As a result there may be a reduction in yields as well.

Certain beds in my garden are already kaput. But there is a silver lining in that. It gives me a chance to plant a green manure crop, which I don’t often get to do.

The terms green manure and cover crop are basically synonymous. Green manure is a crop that will be turned over into the soil while still growing, a cover crop may or may not be turned into the soil right away.

These types of crops are great for recovering soil nutrients from the soil and holding them until next year’s planting season. Some soil nutrients such as nitrogen are easily washed down into the soil profile by fall rains or melting snow putting them out of reach of most garden plants. Much of that valuable garden nutrients that you worked so hard to build up could be lost.

Multiply the nutrients over hundreds of acres and you can see why farmers use cover crops to save money and protect the environment at the same time. Nutrients that stay in the field will not get washed into steams and rivers where they end up being a source of water pollution.

In other words, green manures effectively “mop up” nutrients and hold them in place until they are needed next year.

In a garden situation, the biomass that a green manure crop adds to the soil may be more valuable than the nutrients they conserve. You really can’t have too much organic material in garden soil.

A cover crop also provides a better habitat for soil microbes to flourish as opposed to bare soil.

Planting cover crops is a fairly advanced technique for home gardeners even though it is very effective for both vegetable and flower gardens.

If this is your first time planting cover crops, consider oats, yes the same plant that is harvested and used for making your breakfast cereal. They make a very effective cover crop.

This time of the years we are looking for a plant that will make quick growth and oats fit the bill. Even though they grow quickly, they should be planted very soon.

The other big advantage that oats have is that they will die over winter leaving a mulch on the soil surface that can be tilled in next spring. That also eliminates the possibility that they may become a weed in your garden. I’ve had winter wheat come up in the spring — seeds from straw mulch — and before I knew it they became a problem. Have you ever tried to pull up a well established clump of wheat? They’re pretty tough plants.

Planting oats is much like planting grass seed except the seed is much larger.

 

Oats ready for planting. Note that they still have their outer covering, the hull surrounding the seed
Oats ready for planting. Note that they still have their outer covering, the hull, surrounding the seed

Sow oats at a rate of two or three pounds per 1000 square feet about an inch deep. Farmers use an implement called a seed drill to plant oats. The easiest method for a gardener is to broadcast the seed by hand, then till very shallowly with a tiller. Finish off by lightly pressing the area down so the seeds make good contact with the soil.

Farm supply stores sell oat seed however you may have to go online to buy small quantities.

Bob