Solarize Your Garden to Control Weeds and Pests

Solarization is a safe chemical-free method to render a garden plot weed and pest free.

In a nutshell, solarization uses transparent polyethylene plastic placed over wet soil under a hot summer sun to raise the temperature of the soil.

Why Solarize?

There are many ways, other than solarization, to kill pests and weeds in a garden.

So why solarize?

Various chemicals and poisons will kill weeds and garden pests, but they can be risky to handle, and they introduce unwanted toxins into the garden.

Repeated plowing and tilling will kill most weeds and seeds, but it does not kill all pests, and some residual weed seeds, eggs, and larvae will always be left, so this is not an optimal way to remove pests and weeds.

Solarization, when applied properly will kill nearly all pests, weeds, and seeds with the possible exception of nematodes. Solarization has the additional benefit of killing many soil borne diseases such as tomato wilt, that home gardeners are otherwise powerless to control.

How to Solarize

1. Prepare the area. Solarization works best on rectangular areas. Solarization works best if the area is plowed, tilled, and flat, with no large dirt clods or clumps sticking up to create air spaces between the plastic and the soil.

2. Wet the soil. Apply a uniform spray of water to the area and thoroughly wet the soil. Apply as much water as the soil can hold without creating pools of water. The solarization process depends upon the soil being wet. If you have time, spray the soil, wait a few hours, and then spray it again.

3. Dig a trench around the area to be solarized. It is most important to seal off the area to be solarized. The best way to do this is to bury the plastic around the edge of the area. When you dig up the soil, leave it on the outside of the solarization area, so you can push it back on top of the plastic, once you have laid down the plastic.

4. Spread the plastic. This works best if you have a helper. Lay one edge of the plastic in the trench you dug,and then cover it with dirt to seal off the area and hold the plastic in place. With your helper, spread the rest of the plastic and then seal off the rest of the area, by covering the edges of the plastic with dirt.

5. Remove the plastic. After about six weeks remove the plastic. The solarization process is now complete. Allow the soil time to dry in the sun so it becomes workable, and then plant crops as usual.

Choice of Plastic

1 mil transparent polyethylene plastic is economical and works well. In windy areas 1.5 mil plastic may be better, because it is less likely to tear or puncture. Bear in mind that thinner plastic reflects less solar energy, resulting in higher soil temperatures.

Conclusion

Solarization is a cheap, easy, natural way to rid a garden plot of pests, weeds, and disease. For home gardeners, it is more thorough than any other method, and it has the side benefit of leaving no toxins or chemicals in the soil.

Sources:

http://ceamador.ucdavis.edu/files/942.pdf

http://www.thisland.illinois.edu/57ways/57ways_15.html