There is a projected hi of 108 degrees F today. Its a great time to solarize soil! While most instructions say 'mow the area first', I don't think its necessary at these temperatures. I have some knee high weedy spots. The first patch I laid down plastic after a rain, but now with no rain, I am using the sprinkler to soak the area after stomping down the vegetation. Float on a sheet of plastic. Actually I am using a double sheet, but some instructions say a clear sheet of 2 mil plastic will work fine.
Seal the edges. I am using soaked cardboard, and also some old roofing shingles to hold down the edges. Then let 'cook' for 4 to 6 weeks.
Actually after only one week, the first area that I laid out looks brown and sufficiently dead to reuse the plastic in another spot.

Soil solarization is often used if there are diseases in the soil. But it also is a no-sweat way to clear a piece of your property that is overgrown. Just cut down brush and small trees. I just leave them laying there. Stomp. Water. And apply the plastic.

I've solarized a couple of areas using a heavy tarp held down with rocks piled on the corners. It works pretty much any time of year. I solarized a plot of soil that was healthy turf grass for about 8 weeks through February and March - after having turned the soil over with shovel - and it is now virtually weed free and growing roses like crazy. I failed to seal the edges, and there was a bit of space near the edges where the outcome was less than perfect, but the overall result was stunning. There are a lot of overgrown spots on my property, so the tarp is employed full time. BTW, an old rubber rug underlayment works pretty well, too.

I am using the clear plastic to kill off the surface vegetation -- no shoveling required. It has not worked in the shady areas, but in full sun it is a great way to kill weeds and prepare soil for a new garden.

Well, I was in a hurry. And it was in the middle of winter. The darkness killed the grass and other weeds quite effectively. Not too much seed material made it to spring, either. Not sure why.

Seems to me if the soil gets too hot, it kills any beneficial flora that help plants flourish. Do you re-introduce mycorrhizae when you plant?

So why do you use clear plastic instead of something that doesn't admit light?

Here is a pretty good comparison of which materials do what in solarization.

http://www.waynesthisandthat.c...

I have used mainly cardboard, black plastic and clear plastic. The main reason for using clear plastic is the depth of treatment--I am trying to kill a bad infestation of Asian wisteria. the roots, like kudzu, go deep into the soil, and then pop up all over the place. All know if I see any shoots next summer, but it looks like the clear plastic plus HOT weather in full sun is working. In other areas I use cardboard--but wisteria roots, and also ivy will come up through the cardboard. It has constantly to be renewed so it is not a permanent solution--at least against the woody vines Im trying to get rid of.

As for beneficial flora, you want the beneficial flora that goes with the plants you will grow later--not the flora that has been colonized by the weeds and favors those. It might be a good idea to put in a fall cover crop to recondition the soil after solarization.

PS. If you've ever had a round of antibiotics and wound up with a queasy stomach--you have a good notion of what soil is like that has been depleted of microflora! Probiotics for us, mycorrhizae for the soil!