2

So this year, a lot of my inside potted plants got attacked by powdery mildew and other afflictions. All affected were previously given soil that I sifted from the composter that is on the porch of our building. Likely, some people in the building previously discarded sick plants there, not knowing the spores may survive quite a while.

I was thinking in general, when taking soil from outside to use for potted plants, would it help to let it dry and then heat it to say 60°C (140°F) so that a lot of various pathogens perish? I think some diseases may not even present in outside plants that get enough sun, but may still hurt the ones in the inside.

Tomáš Zato
  • 155
  • 5

1 Answers1

1

Yes, heat will kill Powdery Mildew including spores according to this paper.

Powdery mildew spores and mycelium are sensitive to extreme heat and sunlight, and leaf temperatures above 95°F may kill the fungus.

To destroy all organisms you will have to use an autoclave

Gyrfalcon
  • 1,305
  • 2
  • 6