If it’s commercially manufactured and purchased in a bag, it’s already sterile.
If this is dirt you’re digging out of the ground or re-using from one bed to another or in pots and you’re concerned about weed seeds and/or disease, or you have an area that has already caused you a crop failure, then here’s a good primer on how to sterilize soil:
https://morningchores.com/how-to-sterilize-soil/
I’ve never had this issue. Soil in my garden beds has been dug from our very ‘clean’ pasture (bottom soil; nothing has ever been grown on it other than grass for cattle) and amended with our own home-made (Mule & Steer manure and straw bedding) compost.
Just remember that sterilizing soil kills all the GOOD STUFF in there, too.
Has anyone else had this situation? If so, chime in! :)
Yes, my intent is to re-use some garden soil* and a concern is the killing of all the good stuff...
*My biggest problem is that squash and such seem to do well until just about the time fruits start to develop, then they weaken and produce poorly or not at all. Same for melons. I put Okra in the same spot last year and it thrived and produced way more than we could use. Peppers there did “ok” and eggplants so-so. Soil testing says nutrients and so on are good. Tomatoes generally do well.
I can’t afford to buy new soil for this much area / volume. I “can” apply Preen to kill weed seeds, as all plants are started in small containers with purchased soil and then transferred to the garden once a few inches high, or more. But diseases and harmful nematodes and such are my concern.
I’m still thinking an afternoon in a hot car would kill diseases and such, leaving me with something not too far from purchased soil?
Unfortunately, most of our property has hickory trees, plus a couple walnut trees. So, that soil has juglone in it, and I can’t use it in the garden. I cut down several intermediate (~ 4” trunk) walnut trees last summer whose foliage began 50-100 ft. away from the garden area, in hopes of reducing juglone in the garden area. (Leaching and leaves blowing in in the fall may be a problem, and on still summer days you could readily smell the stuff.) As tomatoes seem to do reasonably well, I SOMEWHAT doubt juglone in the garden is the problem, but I’m unsure on that score. In any event, the closer walnut trees are now gone, and the closest hickories are over 100 ft. away.
What a temperature of ~160 deg. for a few hours might do to juglone I have no idea, but juglone does gradually decay with time, of course.
Thanks!