Solarize: Kill Disease and Weeds, Improve Yields

We used to believe that certain plant disease pathogens lived in the soil and could not be eliminated. Pestilence like verticillium wilt fusarium wilt were believed to be with us and just had to be tolerated. In the past ten years, some enterprising Israelis came up with solarizing. It is an excellent way to kill weeds, fungus, and general pests that live in your soil. It is all natural and requires no chemicals. Solarizing has been tested at universities across the US and by extension programs all over the country. It must become part of your arsenal in developing and maintaining the healthiest garden on your street, in your county…you get the idea. You want to feed people healthy food. What is healthier than chemical free pest control? How does it work?

The process produces lots of high heat and humidity in the soil which pasteurizes the soil destroying all the pestilence contained there. It rids your plot of harmful bacteria, fungi, many nematodes, almost all insect larvae, and the weed seeds near the surface of your soil. Testing has shown solarization to be effective against the verticillium wilt in tomatoes, potatoes, and eggplant. It whacks fusarium wilt in your tomatoes and onions. Solarizing also eliminates rhizoctonia in potatoes and onions and nematodes that attack your potatoes and other crops. Unbelievable isn’t it? Testing has shown all of these benefits and more.

Solarizing also helps your soil produce healthy strong plants. Solarized beds have been documented to produce greater yields after the process is complete. It seems that the bad juju is eliminated and the good organisms survive and thrive. Fungi that play a role in nutrient utilization survive the heating process. Very Cool!

Now that you know what solarizing can do for you, how do you do it? The best time to solarize is in July and August when days are long and hot. Solarizing your bed is very straightforward. Loosen the top one foot of your bed with a fork, digger, tiller, or your bare hands (probably want to avoid that last one). Late in the day, water the soil until it is soaking wet (much wetter than a regular watering of your garden). The next day, cover the bed with plastic. Use clear film that is three (3) to six (6) mils thick. Do not use black plastic. Black plastic will not work. Use clear film. Cover the edges of the film with soil and wait four (4) to six (6) weeks. If it rains during the period of waiting, sweep the water off the top of the plastic with a broom. Do not put holes in the plastic as this will let the heat escape.

After you are done solarizing, you can plant a late fall crop. Don’t disturb your soil much. While the weed seeds at the top have been offed, the ones six or more inches down may not all be dead. It looks like you can expect the effects of solarizing to last for four or so years as long as you practice good soil and garden management. Strike back the the disease and weeds in your organic vegetable garden, solarize your beds this year!