Leave the roots. They generally rot fast and there typically are so many roots that you could never remove them all anyway.

It's all good organic matter for your soil.

Wayne

The fungi that decompose the roots are essential for good soil. If you pull the roots you lose the population of those fungi as well as the beneficial byproducts of the roots' decomposition.

Plant roots add organic matter to the soil, so they should be left in the soil they grew in just as some of the top growth should be left on the soil to add even mroe organic matter.

Dosent this depend on the plant? I've always been told some you should remove, like tomatoes, because of the possibility of diseases, like blight. Just asking?

If you have a good, healthy soil your plants will not get any diseases that would be of concern, and the way to get a good, healthy soil is to put a lot of organic matter in that soil. People that garden what is today considered the "conventional" way, dumping synthetic fertilizers on their soil and not adding organic matter will have disease problems.

I agree that healthy soil should keep the disease away. If you were worried about blight or any other common garden disease, I would sprinkle ordinary (and inexpensive) corn meal on the soil periodically. Research at the University of Texas at Stephenville back in the 90s indicated that corn meal could rid the soil of disease equally as well as the traditional method of crop rotation. For tomatoes and plants of a similar size I would scatter one heaping handful under the canopy/rootzone of each plant.

I'm very interested in reading this study you mention. I can't seem to find it. I just keep finding a lot of contradictory articles concerning it. Some say it works because one reason, some say for another. Most say Texas a & m found it to work, though, for the crops studied. One said the study was not repeatable and even Texas a & m admitted it was thus not a fact because the scientific method dictates otherwise. Problem is, I can't find anything directly from the source that makes any claim at all. I also found several garden web posts that both supported and warned against it's use. Also, the articles I read all state fungus, not disease. Fungi can cause disease, but they aren't the only thing. TMV isn't caused by a fungus at all and hit Indiana hard. All the articles I just read specifically stated these tests were on peanuts and corn. No mention of any other crops in the ones I read.

Also, healthy soil inhibits disease, but not 100%. There are many instances where disease will infiltrate no matter the health of the soil. Transplantation of plants with disease (somewhat common from some big box garden centers), insects passing viruses, not washing your hands and tools after working with another area that has a disease, floods (which seem to be getting more and more common), animals burying things in your garden like chipmunks will do, etc. I found a couple of walnuts buried in my garden last year. The nearest walnut tree is several blocks away and I know I didn't bury that stash. I find seeds bluejays bury all the time from the feeders, which are not from my garden so if they contain disease I wouldn't know until it's too late.

Canuckistani, I liken healthy soil to nutrients for human health. Eat right and take care of yourself and your chances of living longer and a better quality of life are higher. But, that doesn't make you impervious to disease and you will eventually get sick from something. More so if you hang out around illness. If you have a diseased plant, uproot it. If not, leave the roots if they don't come out when you clean up the garden. If you have a virus, uproot and follow recommendations on rotation for that specific plant. For example, TMV can live in the soil for years and there is plenty of info on how long you should wait to plant affected plants in the same spot again. Like the others, I've read that keeping roots of healthy plants in the soil when cleaning the garden contributes to good soil health.

Previous discussion on plant diseases complete with links to a couple of Universities in the States.

Lloyd

Here is a link that might be useful: Plant disease discussion

I'm very interested in reading this study you mention. I can't seem to find it.

Plugging these words (stephenville peanuts disease cornmeal "texas a&m") into Google, the first response is

http://stephenville.tamu.edu/pp/pdncr/index.html

The website has been updated, but not changed, since 1995 as far as I can tell. The organic community has been using ordinary corn meal to successfully fight a variety of Sclerotinia, Sclerotium, and Rhizoctonia types of diseases in lawns and gardens since 2000...as far as I can tell. Since 2001 I've absolutely relied on it to kill every kind of fungal disease I get on my lawn. My family likes to leave stuff on the lawn so the air can't get to it. Fungal disease ensues and I apply corn meal. Nothing else I've tried has worked like corn meal.

There is a large crowd of skeptics that refuse to try it but still knock it (or research it until completely confused). Of those of us who have gone ahead and tried it, I'd guess 90% are having success.

Will the cornmeal also kill off beneficial Mycorryzhae as well??

I can't answer that exactly. First all the cornmeal doesn't do the killing. It works like this. Corn meal attracts certain fungi that decompose the corn meal. Those fungi attract a family of fungi called Trichoderma (try ko DER ma). The Trichoderma is the fungus that "eats" the other fungi. It grows in population and once the target fungus is gone, the Trichoderma starts looking for other fungi to "eat."

I have a feeling the Trichoderma species need more fresh air than the mycorryzhae need, but I can't say that for sure. If so then the fungi living deeper underground would be more safe. Or it could be other factors involved.

In any case I have been using corn meal every year since 2002 on my lawn. I have fungus issues. If my circumstances ever change, maybe I can switch to alfalfa pellets for a full season and see how that goes.

I tend to leave roots in the soil to rot in place. I feel pulling up the roots disturbs the soil structure and lets it pack down, while leaving the roots in place eventually allows them to rot in place. After the roots degrade, the space they occupied becomes little tunnels for oxygen and moisture to penetrate.

Biodiversity in the soil is the key, the Soil food Web.

Here is a link that might be useful: Disease Suppression with Compost

Dschall good to see you on here as well as the lawn forum. Where do you find 50# bags of corm gluten meal? I went to the feed store and bought 50# of SBM and asked about CGM and they didn't sell it.

There was an interesting discussion quite a while ago about roots attracting worms, link below.

It still seems to me that the roots of dandelions attract more than their share of earthworms. And rotting roots attract them in general. I found this explanation on one discussion board:

"The rhizosphere (soil area around roots) is moist, nutrient rich, supports
the bacteria and protozoa that worms need, and has an ongoing production of
exudates from the plants photosynthetic processes and other activities, and
may support nutritious fungus that worms need to eat."

This fall I cut off just the bean tops so the N-fixing nodules on the roots would feed the soil.

Kimmsr will probably set me straight about something or other.

Here is a link that might be useful: root exudates attract earthworms

Credit where credit is due, Kimm, that was a most excellent link.

Lloyd

Can I just use regular corn meal that I buy in the grocery store ?
Or does it have to be special corn gluten ?

Corn gluten meal is for pre emergent use and is also a stronger source of protein/nitrogen. For fungus issues, use ordinary corn meal.

...to tag onto bpgreen's message, both are sources of protein for the soil microbes. CGM has much more protein per pound because a lot of the sugary part of the corn was ground off to make corn syrup. CGM was thought to be waste material and has been fed to animals for a long time.

I buy plain, unmarked (for preemergent) CGM at any of several feed stores. They are mostly independent so you should call around. When one can't provide it, ask if they know someone who might. I've discovered many feed stores I never knew of by asking that question.