Well understood by whom? By commercial farmers? Certainly. By the average home gardener? Maybe not. By market gardeners who need to grow as efficiently as possible on fairly small ground in order to produce maximum yields needed for financial survival? Probably.

One key thing to remember is that you get the best results when you match up the cover crop with the targeted disease or diseases that plague your soil and that need to be dealt with. Some cover crops helps with some specific pathogens or pests, but not with all. It also matters how you use the cover crop. With brassicas, for example, it is important to cut down your cover crop (mowing works just fine) and chop it up or cut it up in order to rupture the cells. When the cells are ruptured, that's when they release the compounds (that might not be the right word...maybe agent or chemical would be better, I don't know) that serve as a natural biofumigant. So, simply growing the cover crop isn't enough----it also is all about how you use it.

Commercial growers in California's agricultural areas are masters at using cover crops to improve their soil in many ways. Otherwise, the pest and disease build-up/accumulation in their soils would make it impossible to grow crops there year in and year out for decades.

Organic farmers and gardeners have long used cover crops as a regular part of their rotation, going back many decades. I am not sure how long those same cover crops have been studied and used in commercial non-organic farming, but research has been going on in that area for several decades. One of the earliest studies I read was about the use of clover to combat the build-up of cotton root rot in soil where cotton was cropped continuously. I think that one dated back to the 1950s or the 1940s. I think that research nowadays is better at figuring out how these cover crops work, whereas in the past it was merely understood that they work.

I've given Dawn the heebeejeebees by mentioning how the soil in the area of the wild Johnson grass (Sorghum halepense) is of excellent tilth and health. You make me impatient to get down into that area of soil because last year saw the Johnson grass, buckwheat and Giant Mustard. I'm curious why white mustard? Were they using white mustard because of a double whammy by way of crop production or does the White Mustard have better cover crop qualities than other species of mustard?

If the sweet sorghums or the hybrid sorghums are as invasive as Johnson grass, I'd only use it as a last resort. In fact, I'd never use it, because I don't till or plow. It's easy to get out by hand, but hard to keep up with its fast growth rate.

(I didn't realize broomcorn is a sorghum. That would be way fun!)

Dawn and Bon,

As usual, I'm a little smarter now. It feels good to know there are effective techniques that don't involve pouring chemicals on the ground.

I had lunch with a couple of aspiring young gardeners today. My only advice was to get their soil tested, and get started by putting some seeds in the ground.

There are those who talk about it and then there are those who do it.

Bon, I'm well aware of how soil near Johnson grass has great tilth but I don't care. If bermuda grass is "the devil", then Johnson grass is "THE DEVIL" and I abhor them both. : ) I won't apologize for abhorring them either.

I also don't use sorghum very often because just knowing it is related to Johnson grass does give me the heebie jeebies, but when I grow it, it is not nearly as aggressive as Johnson grass. Johnson grass is not at all hard to control if it is in a place where you can cut it down. By repeatedly cutting it down, you starve its huge rhizomes (eventually) and they wither and die, although it can take years for this process to play out. It is a problem in my gardens because it springs up directly underneath the fenceline where it is impossible to dig....by digging it out, I leave soft soil and holes where rabbits and skunks and other varmints will come right back and dig out the soft soil and tunnel under the fence. My favorite sorghums aren't the ones commonly thought of as cover crops, they are the ornamental ones like broom corn. When I grow broom corn it gets at least 12' tall. I plant purple hyacinth beans to climb the broom corn once it is 5 or 6' tall and they make a spectacularly forest of cover crops or ornamentals. From a distance, in August, the combination of broom corn (in mixed colors) and purple hyacinth beans are the prettiest sight around for miles and miles. It stops traffic. I cut them down after the season ends. Between the two of them, they'll shade out regular Johnson grass pretty well and that's mainly how I use them....at the edges of the garden where Johnson grass tries to grow and creep in underneath the garden fences.

On the mustard plants, what little I remember about them is that as they decompose they release glucosinolates that serve as natural soil fumigants and in some studies, these natural glucosinolates are a more effective soil fumigant that commercially produced fumigants that are synthetic in nature. Some mustard types release more or better glucosinlates and Johnny may remember if they mentioned any specific varieties on the radio broadcast he referenced. I believe yellow mustard has the widest application for controlling the largest variety of common soil pathogens.

You also have to take great care to match your cover crop to the problem you're attempting to address. Using the wrong cover crop can actually increase disease issues, and I'm not sure if that is well-studied and well-known, though I assume it would be.

Dawn,
The presenter has used Yellow Mustard. However, he says Buckwheat and Sorghum perform fumigation chores too.

I am still looking for crook neck sorghum seed because that was the first crop I ever helped grow. I could barely climb high enough on the grain drill to pour the seed in the bin. I am convinced my chickens would love it cracked.

I have been feeding the green cereal rye in my back yard to my chickens. I give them a big fist full every day. You should hear what they say about me. One more benefit of cover crops.

Dawn, that Johnson grass is only there because I haven't gotten it all out, yet. And in the areas where I did remove it, but not planted sufficient the Bermuda is creeping in. At least the roots of the bermuda are not 3 foot deep as was before Mr. Coleman plowed deeply, but it will if I don't hustle. Some of the largest stolons (? roots) on the Johnson grass were 1/2" thick. They've been there for years. Skin crawling experience, here. ha

I love the broomcorn and hyacinth combo. I'm tempted to go order the broomcorn after I finish typing.

You bring up an excellent point about cover crops introducing their own diseases and problems. That'll be a good subject to study up on. I appreciate you informing that they might need be cut up to release the necessary soil goodies. I plant to use mustard in addition to daikon radishes, buckwheat and clover this year.

Mr. Coleman, keep us updated. Very interesting progress you have going on.

Best thing I ever did was raise red wigglers. Learning how to keep worms happy and healthy is a giant leap into learning how to keep soil happy. Sometimes I think I know more about soil biology than growing vegetables. And I think it's an excellent foundation. If anyone asked me for gardening advice, I'd probably tell 'em to start learning about soil microbes and to raise worms.

Johnny, If the crookneck you are looking for is Vilgore Crookneck, all you have to do is join the Seed Savers Exchange. SSE has separate mechanisms for distributing seed. The public catalog where they sell selected varieties shipped from SSE offers just a tiny smidgen of what is available through the private member listings at SSE. You don't have to be a member to order through the public catalog. The private catalog listings of offerings available to members only now is available for viewing online, but in order to obtain anything in the exchange listings, you have to be a member. If the Crookneck you remember was grown here in OK, then Vilgore Crookneck might be exactly what you're looking for. I've linked its description below.

I grow lots of stuff for my chickens, and they love rye grass. It is ridiculously easy to make a chicken happy in wintertime. A little bit of fresh greens will do it every time......

Bon, I love the mixed colors of broomcorn. If you want to grow one of the sweet types of sorghum that were used back in my father's day to make sorghum syrup, Southern Exposure Seed Exchange has the best selection I've ever seen in a public catalog. Then, all you'd need is a place to process the sorghum and you'd be producing your own syrup. I believe it involved a press and then boiling down the stuff that the press squeezed out of the stalks of sorghum.

Earthworms are my favorite soil improvers. All I have to do to attract new ones to poor, compacted clay soil that they've stayed away from is just to put down cardboard and wet it down good. They come to eat the cardboard and fix a whole host of soil issues as they do it. What could be easier?

Vilgore Crookneck

Amy,

Klaas Martens is the fellow I was listening to in the above mentioned web program.

Thank you very much for this. I will hand it out at our next board meeting. There may be a test for the board members later. ;-)