Saturday, May 12, 2012

Baking Soil

This is a post reprint for May 6-12 International Compost Awareness Week. This important educational program is sponsored by the US Composting Council, with the theme of Compost! …Replenish the Earth for Generations, and supported by the Compost Council of Canada, with the theme of Give Back to the Earth … COMPOST!

No, not mud pies. I'm trying to use the power of the sun to help me rid the potting soil from my potato barrel of pests, primarily slug eggs and some small wriggling worms which probably were potato tuberworms. I don't remember seeing any slugs on my potato plants, but there are definitely eggs visible in the soil. The worms are no longer visible, but I'm sure there are eggs still waiting to hatch.

Solarization is the process of using the power of the sun to sterilize soil. It's best done during hot summer months, but at least one website stated that it is somewhat effective during cooler months. It's worth a try. In most cases, soil in garden beds is covered with plastic tarps for 4-6 weeks during summer heat, longer in fall and winter.

I removed the potting mix from the potato barrel and divided it into four plastic garbage bags. To speed things up, I picked out as many slug eggs as I could find. First, I left the bags open to partially dry the soil. Then, I sealed them to start the "baking" process. The soil in each bag was about four inches deep. Also, in a closed environment the heating potential is increased. This will be particularly important now that fall has arrived.

Yes, I probably should have discarded the soil to make sure my potatoes next year have the best possible chance, but it seemed so wasteful. Has anyone successfully removed pests from potting soil? I would love to hear your experiences. -- Margy


  1. I have put smaller amounts of potting soil on trays in a slow oven for half an hour. Yes, it stinks. But it works.

  2. I don't think it gets hot enough out here to successfully cook the soil. But I suppose it is worth a try. MB

  3. Thanks for both of your suggestions. Maybe I'll try a combo of cooking the soil in a heated device and the sun. I have an old BBQ that I could put on low to bake the soil a batch at a time and then put it back in the plastic to hold until next spring. - Margy

  4. Never tried it but I might try it by covering my veggie beds with black plastic. I wonder if the good worms will also die? I'll have to do a little more research.

  5. We've got so many bugs everywhere!
    One natural thing, Ed Lawrence always says to use 1 part dish soap to 40 parts water, spray it on the soil. I use that for whitefly, and all sorts of bugs.
    I do laud you for your floating gardens.
    Greetings from Cottage Country!

  6. Thanks for the tip Jenn. I'll have to give it a try. You know that I don't want to use anything poisonous to good critters, like us when we drink the lake water. - Margy