Soil Solarization can rid your garden of weeds!
Have you heard of soil solarization? Soil solarization is when you use the sun to kill all the weed seeds and pests (insects, nematodes, bacterial and fungal pathogens) in your garden prior to planting and it has the added benefit of increasing nutrient availability and you do not have to add any pesticides.
Soil solarization is simple to do. The biggest downside is that you will be unable to use the garden while you are solarizing it. Those of you in Arizona, and other parts in the West, will not find this to be a problem most years since our hottest months are in-between our seasons. You can garden for a season, solarize the plot, then plant for the second season. Those of you who are growing crops during the sunniest and hottest times of the year could still solarize the plots you are not using or plots that you had a lot of weed or pest problems with the previous season. If you are in a cool or cloudy area than soil solarization will not work for you.
Four steps to soil solarization:
- Clear all weeds and old plants. Anything that could harbor pests must go!
- Level the soil. It will be easier to apply the plastic at later if this step is done. Plus, you need all the parts of the garden to be equal distance from the plastic or you will not get a uniform temperature underneath.
- Irrigate the soil down to a depth of at least one foot. You can use a rebar or thin pipe to determine how deep the water has reached. Push it into the ground until you hit resistance. Mark the pipe and see how deep you were able to push it into the soil.
- Put a plastic tarp over the soil and anchor it down. 1 to 4 mil plastic works best. The closer it is to the soil the better it will work (which is why the leveling step is so important). Leave the plastic on for 4-6 weeks.
The top six inches of soil will reach temperatures up to 140 degrees Fahrenheit and the soil will heat up as deep as about 18 inches. If you remember from the how to compost post, a temperature that high will kill off weed seeds and pathogens (which is also why you want your compost to reach high temperatures). It will also break down solid materials in the soil (just like your compost pile), making those nutrients more readily available.
Your garden bed will be ready for planting at the end of the soil solarization process (4-6 weeks) and you will have a lot less weeding to do in that plot! It is great for those of us who like to have an organic garden. Remember to pick a time of year where you get hot, cloudless days.
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Submitted to Green Thumb Thursday!
great guide, thanks for sharing i had a good read here