sterilizing soil-Help!

Woonsocket, RI(Zone 6b)

I had found on one of the forums, how to sterilize soil in the microwave but I can't find it.
I'll post this question in a few places. I'm starting some annuals and veggies in the new greenhouse my hubby built for me. I,m sure with all I,m planting, I'll need more soil than I already have. I have some jiffy mix, but I,m going to run out before I,m done.Does anyone know how to sterilize soil in the microwave?

Frederick, MD(Zone 6b)

Yes! I have figured it out! For a description of whatnot to do, see my 'Fire in the Hole' thread.... it's quite important not to try this with dry soil!

A big microwaveable container with a lid works best. I have a huge tupperware bowl I've used for bread dough.

Fill the container with potting mix. Add water, at least a cup for every quart of soil, more if mix is really dry. Place the lid on the container loosely (do not seal, you do not want exploding dirt).

Microwave at full power until you see evidence the water has turned to steam (eg, droplets on the lid). Time for this will vary according to how much mix you put in and how powerful your microwave is. For my big container, it's about 8 minutes, but you might check after 4 or 5.

Seal the lid to hold the hot steam in. This is what will sterilize the soil over the next 10 minutes. As a bonus, the steam will penetrate and moisten even stubborn old potting mix that otherwise refuses to absorb water.

This is the first year I've sterilized my mix, but this year I am using leftover mix from last spring, so it seemed even more prudent. So far, no damping off and no weed seedlings either!

Woonsocket, RI(Zone 6b)

Thanks, I'll try it next chance I get.

Woodland Park, CO(Zone 4b)

Wow, do I really need to nuke it that long? One gallon of moist soil takes only 2-3 minutes max to bring it up to 180 degrees. Does this sound right to you? I keep it covered and let it sit till cool. Not a problem with disease of any kind. I re-use soil as well.

Frederick, MD(Zone 6b)

As I said, everyone's microwave is different. I think I'm doing about 8 quarts in my bowl. I played with the time until I figured out how long it took until I saw a good amount of steam. As long as the temperature stays above 180 for 10 minutes, the soil should be sterilized.

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