I'm curious if microwaving soil actually works to eliminate fungi and bugs. Has anyone given this a shot? I know buying more soil is easier, but I want to see if this method is effective.
5 Answers
Using the oven is a better choice! Just spread your soil out on a baking sheet and cook it at around 150°F for about 30 minutes. That should kill most of the unwanted stuff without the risks associated with microwaving.
It might be a waste of time. Even if you kill some pests or fungi, they can easily come back since they're airborne. If you’re dealing with mildew, try reducing your humidity, watering less, or adding a fan. For specific pests, use targeted treatments instead.
Honestly, I think it's not the best idea. Microwaves aren't really made for this kind of thing, and I worry about what could happen to the perlite or small rocks in the soil. Plus, hot, damp soil might smell pretty bad!
I've tried microwaving small amounts of damp soil in a plastic container with a loose lid for about 3 minutes, and it worked for me! The microwave didn't smell afterward, and the soil didn’t have an unpleasant odor either. It seemed like a quick and easy solution, but I can't guarantee it works for all pests.
Boiling the substrate could be a safer option to sterilize it without the weird risks of microwaving. Just my two cents!

That's a good point! I hadn’t considered the smell or potential issues with soil components.