Bill, I too am disappointed. I placed the plastic for about 2 months to kill weed seeds and it didnt put a dent in them at all.

never again.

Bill
Thank you for your post even if it was a failure for you. It is valuable information for others (me).
All summer I thought about how I need to solarize one bed that had nematodes but other things kept delaying me and I felt guilty.
Now I feel less guilty and will plan to use pots instead of that bed and plant flowers there instead.
Between the nematodes and the TYLC virus it's gonna be a struggle but I've got many many tomatoes started in pots to try and get those wonderful home-grown tomatoes.

Denise

Question...do the nematodes mostly attack vegetables and fruits? Are most flowers safe, or just insect resistant ones like marigolds?

Bill & Tony, I'm sorry your efforts didn't pay off. Bill, what would happen if you replaced all the dirt in your raised beds with new mushroom compost or the like? Would the nematodes come up from below, or would 18" of fresh soil or compost do the trick?

Marcia

Sorry that didn't work, but thanks for posting it as it saved me the trouble of trying it. I think I want to try Treefrog's method of digging a big hole, line it with newspaper and fill it with fresh soil and then plant the tomatoes. By the time the tomato roots get through the newspaper they will be done anyway. David please, add to this, if I don't have it quite right. ;o)

Tony, my solarization didn't kill weed seeds either.

Marcia, I have a feeling you've hit on the only sure fire way of dealing with nematodes--just replace the soil every year or so. But it would mean hauling in a lot of compost, and I don't have a truck. And I still like the idea of "working with the soil" instead of just replacing it--but maybe I should just accept this is florida.

Some flowers--like pentas--are susceptible to nematodes. Ohters, like marigolds and black eyed susans, are non-hosts and useful for starving them out.

I going to try basically putting the whole back yard on a rotation scheme. Some spots will be marigolds or zinnias, while other beds will be resistant veggies, like mustard and kales, and others will be susceptible veggies. Every season I shift everything around. I'm hoping that a season of marigolds and another season of a non-host veggie will purify a spot enough to grow say beans or tomatoes the third season. I still don't know if I have enough space for it to work.

Bill

Sorry if this is going to sound a little crazy. The point of solarization is to raise the temperature because nematodes die from heat, right? What if I boil a big pot of water, OK, few big pots and water veggi bed before planting my tomatos. Is it going to help?
Maria

As funny as this sounds, I used to put dirt in an old microwave out on the porch and get the soil smoking and then put it into containers in the 5 gal size. It took some time to accomplish but it worked.

It was one of them HUGE counter top microwaves that could swallow our more modern microwaves with ease.

When the microwave finally died, so did my cooking of the soil, BUT it worked

commercial growers use huge steam-injection machines to "clean" the soil of nematodes (and every other organism!). i have wondered if a rented steam cleaner from the local hardware store wouldn't do the trick... i've played around with them, and they amount of steam they are able to produce is not insignificant. i bet it'd cook the top 6' of soil... which is as deep as RKN live. it couldn't take more than an afternoon to do even a fairly large bed...

Your neighbors would raise their eyebrows at seeing you steam clean your garden! LOL

I have read that brassicas and mustard plants tilled in produce gasses that nematodes don't like. Certain marigolds too. But in reality, the sand we call soil simply seems to disperse any and all organics I've added, and rather quickly. So if you have an endless supply of compost and manure you can probably keep ahead of the nematodes. I don't and haven't put a dent in the RKN population.
Which is why I grow tomatoes either in pots or by using the posthole method Katkin described above. 2' deep, 18" wide, lined with wet newspaper, filled with potting soil & compost & slow release fertilizer. The plants produce plenty and live through their useful life (Oct thru April for me).

Yeah, I could just envision me steam cleaning my garden, LOL.

Does anything prey on nematodes? Maybe there's something we can do to encourage their teensy little predators along while we're trying to kill the nematodes. Anybody know? And as long as we're kicking ideas around, does anyone know if a regular pane of glass jacks up solar heat like a magnifying glass does? I wonder if panes of window glass laid out over the garden beds would work any better than the plastic? Sure would be expensive though, even if it worked.

Old book I have/had says Black plastic over wet soil for solarization and says something about not bothering with clear or other dark color tarps because it isnt worth the efforts.

Anyhow I did square foot gardening in a small 5x10 raised area with 10 or 12" PT lumber frame and never had nematodes... and during the heat of the summers it was covered with black plastic. Tomato vines dont decompose well but most everything else would tilled under there too.

The pnly plastic that works in heavy black plastic. It works best if you have rotated a crop and preferably cabbage, broccoli, etc and then let that decompose with the heat under the plastic. You also need to ensure the soil is wet before adding the plastic and leave it alone uncovered for several months. You can even cover the plastic with a thin layer of old newspapers and keep them damp or mulch. It helps to keep the heat in. My father always planted companion plants next to his tomatoes and we never had any problems in north Florida with the RKN

I've always rotated my beds, used LOTS of organics, heavy mulch and grown up shrimp & crab shells.

For solarization, MacCubbin, Stephens, and many others all say use clear plastic. Black plastic is used for mulch, with strawberries, for example. Covering the ground with black plastic may help reduce nematodes somehow, but it would not be through solarization. Maybe it helps hold in the mustard/kale/marigold gasses that Treefrog mentions.

I have used chitin (extract from shrimp and crab shells), ammended with shrimp shells and eggs shells, in addition to compost. My beds are, as mentioned above, pure organic matter, except for some vermiculite. None of this has stopped the nematodes for me. At best it slows them down enough to get a harvest before the plants die--if I use resistant variety. The nematodes are also getting worse every season despite all of the above.

Hi all, you need more heat!

{{gwi:961276}}


Take that you stinking nematodes! This is a picture of me testing the use of a turkey fryer to heat the soil to 160F. It worked great but does require a bit of work, how it is used is at the end of the tomato growing season the soil that was around the root zone of the tomato plant is dug up and put into the large pot. about 1 1/2 gallons of water are added then the big tourch is lit. After about 20 min the water and soil are at the 160F mark and the flame is cut off. It is allowed to cool for about 12 hours then the wet soil is dumped back into the hole it came from. To make things safe nothing is moved when hot. Yes you could boil water and dump it onto the soil but that might be a good way to get hurt. I have found that by using this technique I can grow tomatoes in very sandy soil, in the same spot each year.

I believe the problem with solarization is it does not get hot enough. From what I have read the use of clear plastic over dark soil will produce more heat then black plastic. (The black plastic itself gets hot but not the soil)

A few years back I made a home made solar oven, (very simple really - just a large box with a smaller box in the middle with insulation stuffed around the sides and bottom. Soil is added to the smaller center box. The top is open and a piece of plexi glass tapped to the top) 150F was the best I could do with this setup. I'm sure solarization is much less effective with all the heat loss through the bottom soil. I have not tested this but it would not surpise me if soil that is down about 4 inches never gets over 110F or so. That is just not hot enough to kill the nematodes of destroy the weed seeds.

Bill,
"Right now plan is to tear out all the wilting veggies, replant veggies in other areas of the garden, and plant the beds solid with the prettiest marigolds I can find for a season or two--unless any of you have better ideas."
Don't use just any marigold, look for the Golden Guardian, I think Parks may have them. Or maybe try some mustard. It is listed as nematocidal in the cover crop section of the Peaceful Valley cat. (groworganic.com)

Karen,
"Does anything prey on nematodes? Maybe there's something we can do to encourage their teensy little predators along while we're trying to kill the nematodes. Anybody know?" I have read that by adding chiten (not spelled correct) you can cause the nematodes to be eaten. Chiten if from crushed shells like oysters I believe.

Hope this helps, DC

Thanks, DC! I'll look for those golden guardians. I've been wondering what sort I should plant.

About cooking soil, I've also heard you can fill up a five gallon bucket with soil, pour in gallon or so of boiling water, and cover it quickly with a lid, leave it for fifteen minutes, and the steam will kill off nematodes and weed seeds. I have had success killing weed seeds this way.

Bill