If I follow the instructions in the article "How To Solarize Garden Beds To Eliminate Garden Pests In The Soil," will I be killing earthworms as well? When I till my garden beds in the spring, they are full of earthworms and I do not want to kill them, but I would like to kill weeds, especially thistle. Any advice? Margaret Brown
Certified GKH Gardening Expert
That is a good question. The current thinking is that solarization may kill some earthworms, but most of them burrow down further into the soil to escape the heat. On the other hand, weed seeds and harmful microbes cannot escape. Solarization produces heat mostly in the top few inches of soil, so deeper soil life would not be killed.