Fluffing to release steam sounds like a good way to get burned; please be careful!

It works fine to cover loosely, microwave until it steams up pretty well (10-20 minutes depending on your microwave and on how much you're doing), then put the cover on tightly -- it will continue to steam and will cool down gradually. If it's steamy for at least 10 minutes altogether, the soil will be sterilized.

Thanks, I hadn't heard this tip before.

I don't do any fluffing and just let the mix cool on its own. Works great.

Ya know, I've been wondering if you could use a microwave for that. Thanks!

Nice tip, thanks.

You can also use a ziplock bag. Just make sure there aren't any rocks in the soil you're sterilizing!

Critt's right about being careful! There's a lot of steam built up.

The only reason I fluff in the first place is to get the sterilized potting mix cooled down in a hurry, 'cause I'm usually ready to sow seeds right away!

Linda

I use a covered casserole.

Beware, this process does make your house stink! I take it right from the microwave to outside to cool, try to minimize the stench in the house. The microwave will be stinky, too. I clean it afterward with an antibacterial cleaner, then let the door stand open for a while.

Karen

I've noticed the earthy smell only lasts as long as the mix is hot and steamy. As soon as it cools down, no more earthy smell...you'd never know it was there...

Hmm, wonder if you could do this on the grill....??

I've been doing this for some time. It's when you use regular garden soil that it really stinks up the house and continues to linger. Commercial potting mixes and seed starting mixes, not so bad.

I'd like to ask what the occasions would be for sterilizing regular garden soil?

Gymgirl said:I'd like to ask what the occasions would be for sterilizing regular garden soil?

When you can't afford to buy the fancy stuff?

I have mixed regular soil (around here, it's a clay) with potting mix to provide a better mix for some of my plants and seedlings, especially lily seedlings. Most potting mixes available here have way to much peat in them or way too much ground up bark. I think by mixing in some of my garden soil it holds nutrients better.

Sounds like a good use for a garage sale microwave to put in the shop!

I just use my kitchen microwave

Karen

I did too, until I found a much LARGER used one, for almost free!

I got that "stink" when I sterilized potting mix in the oven, but the microwave seems fine... maybe because I use a covered tupperware-type container? Of course, the first time I tried there was an awful stench, because I didn't realize I needed to wet the mix thoroughly, and it caught on fire! Little glowing smoky coals! LOL

Obviously playing with dirt is not for the faint of heart!

Critter, I agree, cooking in the oven in much worse for the stench factor, but I definitely get it with the microwave, too. Just not quite as bad.

Karen

OMG dear critter about the fire :O That's a good point though. Peat is EXTREMELY flamable and alot of mixes contain a high content of peat so everyone please be carefull and play safe

Good tip gymgirl