Soil Solarization or How I'm Choosing to Embrace the Desert and Use it to my Advantage

This past weekend temperatures in Phoenix reached nearly 120 degrees in the shade.  Needless to say, at temperatures that high, it is difficult to get anything to grow well.  We do have a few things that I am trying to get through the summer, but for the most part, we have begun deconstructing our gardens and are planning to hunker down for the summer.  I’ll spend the next few months dreaming of the fall, planning gardens and ordering seeds.  Sounds like the winter for a lot you, doesn’t it?

However, for the first time, I’m using the sun to our advantage.  I am going to solarize several of our gardens and use the Phoenix summer to my gardening advantage.

Solarizing is the process of laying clear plastic down over your garden and concentrating the sun’s energy in the top 12-18 inches of soil.  Temperatures will easily get above 140 degrees underneath the plastic.  This has the benefit of:

  • killing weed seeds
  • killing insects and nematodes 
  • killing many fungal and bacterial plant diseases.
Here’s what you do (and believe me, it’s simple):
  • Get rid of all the plants in the area of the garden that you plan to solarize
  • Level and smooth the soil
  • Irrigate the garden so that the soil is moist.  This will increase the heat conductivity. 
  • Lay clear plastic – over the surface of the garden and secure it.  (I used bricks that we had sitting around.)
Here’s what I used.  It may be a little thin but I already had it and if it begins to fall apart, I’ll just replace it. 
Solarizing is perfect for Phoenix because it is said to work best in areas where the summer is hot and generally cloudless.  If you have a cooler summer or a lot of cloudy days, you might actually create a greenhouse for the weeds and see increased weed growth.  So take that into consideration.  
Finally, solarization is great because it increases the nutrient availability for future gardens.  As the moist soil under the plastic begins to heat up, the organic matter is mildly cooked and the solid material begins to breakdown and create a nutrient-rich liquid.  When you go to plant in 4-6 weeks, you will find that these nutrients will be readily available to your plants.  
I am really excited about this.  We’ll see in the fall if there are any beneficial effects but I am hopeful. 
Have any of you ever tried to solarize your soil?  
In writing this post, I referenced a recent article in Vol 60:3 of the Magazine Organic Gardening.  The article was titled “Soil Solarization: Harness the sun’s power to defeat soilborne pests and pathogens.” If you haven’t checked this magazine out before, I highly recommend it. 

Books on the Topic:


Green Thumb Thursday Linkup

Standard, legally required, Endorsement Disclosure: In order for me to support my blogging activities, I may receive monetary compensation or other types of remuneration for my endorsement, recommendation, testimonial and/or link to any products or services from this blog.

Recent Posts: