Vermicomposting in the cold-climate apartment - Pasteurizing

Monday, January 13, 2003

Pasteurizing soil in the oven

I don't do this anymore (see below), but when I did it, I noticed no malodorous affairs afterwards. For an hour, perhaps, the oven smelled of baked soil (actually baked worms and baked worm eggs, and baked (sob!) baby worms), but it didn't affect my cooking, nor the guests who ate my home-baked bread etc.

Pasteurizing soil by frost

Placing bags of soil on the balcony over the (Toronto) winter won't work. It will kill the worms, but eggs survive freezing temperatures, so once the soil is thawed, warmed and moistened, the eggs will continue their cycle.

Pasteurizing Soil in the sun

Placing bags of soil (I use those 1-litre clear plastic milk bags) in full sunlight during warm weather will, I believe, bake the soil sufficiently to kill off any worms, worm eggs, and sundry other large (by comparison) animals.

Why pasteurize?

I know a bit more about the soil, now. When I kill off the worms/eggs I also kill off most if not all of the healthy life in the soil, right down to the bacteria. This is not good for the plant roots, as, I believe, the plant roots work in conjunction with bacterial growth to obtain nutrients. Don't quote me on this, I'm no soil scientist, but it's based on what I've picked up elsewhere.

Large Tub Vermicomposters

I'm now placing worms IN my large tubs (15-litre and above). Large tubs, such as those that support small shrubs indoors, seem to benefit greatly from the addition of about one dozen Red Wrigglers and the occasional apple core. One-gallon hanging baskets with creepers seem to benefit.

The worms aerate the soil, provide castings, and generally do what they are designed to do. The population stabilizes to the container, and the plant growth has, as they say, to be seen to be believed.

Some people now shun Vermicomposting Bins, and just bury their food scraps into about 12 to 20 plant tubs in rotation. Makes sense to me.

Conclusion

For some reason I thought that pasteurizing, to get rid of worms, was a good thing. I choose not to do it anymore, because I've seen the benefits of having worms in the plant pots.

Red Wrigglers eat only the bacteria that thrive on dead/rotting material, consequently Red Wrigglers can't eat live plant material, such as roots.

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