How to Solarize Your Organic Garden
Soil Solarization is the Green Way to Sterilize Garden Soil
Jul 13, 2009
Organic gardeners like to say their soil is "alive". Unfortunately, organic soil can also be alive with harmful organisms. Destroying these critters before they destroy the garden is a necessary evil, even for organic gardeners.
Why Does Organic Soil Need to be Sterilized?
Nematodes are microscopic worms found in all soils, particularly sandy soils. Nematodes live in and feed on plant root systems, and can kill vulnerable garden plants in a very short amount of time. Harmful viruses and bacteria overwinter and in the soil, waiting to attack and kill garden plants.
How Effective is Soil Solarization in an Organic Garden?
Although soil solarization is not 100% effective, it is the best and most ecologically sound way to rid organic garden soil of nematodes, bacteria and viruses.
The summer sun is more intense because it is closer to the earth, which is why soil solarization works so quickly. Within the three months of summer, organic garden soil can safely and effectively be rid of bacteria, grubs, worms, and other harmful organisms.
How to Prepare the Organic Garden Area for Soil Solarization
Removing the grass and weeds from the garden before soil solarization isn't necessary. The heat destroys them and leftover weed seeds. The soil does need to be cultivated to a depth of 12 inches. After the garden soil has been turned, water well for 30 minutes or more.
Covering the Organic Garden Area Properly for Soil Solarization
To cover the garden area, dig a minimum 6 inch deep trench 12 inches wide around the edge of the garden. Cover the area with a heavy gauge clear plastic. Make sure the plastic covers the whole area, including the trenches.
Do not cover the soil with black plastic. Black plastic absorbs most of the heat, therefore only transferring heat to that part of the soil that is in direct contact with the plastic. Clear plastic allows the sunlight to travel through, into the soil, where it is trapped. This enables the sunlight to heat the soil to much higher temperatures, and be much more effective.
Once the garden area is covered, refill the trenches with the soil removed from them, covering the edges of the plastic. Sealing the area to keep the heat and moisture in is very important. The tighter the plastic is stretched across the area, the better the soil solarization will work.
Landscape timbers or boards can be laid across the plastic in several spots to keep it from billowing up from gasses released during decomposition,
Leave the plastic over the garden area for at least 30 days, or until the next planting time. After removal, allow the soil to cool for 24 hours before preparing for planting.
The Downside of Soil Solarization
One drawback to sterilizing your organic garden with soil solarization is that the beneficial bacteria are also destroyed. Those beneficial bacteria can be replenished by adding some well rotted compost and manure to the soil. If compost or manure is not readily available, there are several brands of powdered beneficial bacteria that can be added to the soil.
Soil solarization is an effective green and natural sterilization method, which helps insure the best growing conditions possible for your healthy garden.
 |
