On 03/09/18 14:23, Judith in England wrote:
A friend of mine is using an old microwave to sterilise soil before
using for cuttings/seeds etc. in his greenhouse.

Is it worth doing?

Will it kill off "good things" as well as bad?

Any comments?

I've never bothered cleaning old pots, let alone sterilising them. I
suppose I've lost some seedlings through one pathogen or other, but
really I doubt it's made much difference. If some seedlings have a
propensity to damp off, I doubt clean pots will make a difference, as
most of these pathogens are air-borne. And if you seal the propagator
aren't you creating the perfect conditions for damping off?

And why use soil for cuttings? In general, you use
peat/sand/vermiculite/perlite/commercial compost, etc. The only time I'd
"use" soil is taking cuttings from rose prunings. etc which are stuck
straight in the soil in a slit trench. No sterilisation there!

--

Jeff