On 05/06/2020 14:04, Nick Maclaren wrote:
In article ,
Jeff Layman wrote:

My problem is with seed compost, because I can't think of how to
sterilise the soil without acquiring another large device - and I have
no space left for storage.

Have you got a problem with soil-borne pathogens? I just wonder because
I not only do not sterilise any seed compost I use, but I no longer wash
the used pots I sow seeds in. I have had problems in the past with
damping-off in seed-trays covered with a plastic propagator lid, but not
recently, and I can't remember any recent problems with seeds sown in
small pots.

Oh, I gave up washing pots some time ago. It's not for that reason,
but to reduce the weed seed load for seeds that are difficult or slow
to germinate or difficult to identify as seedlings.

I do have a problem with soil-borne pathogens, but they don't seem to
be as active in pots, and I don't know what they are. Except for
white rot, eelworms and spraing, which I have identified but do not
affect seeds.

Although it may not be perfect for sterilising, have you tried spraying
hydrogen peroxide solution on the compost an hour or so before sowing?
It shouldn't affect the seeds (except that it /might/ improve
germination of some recalcitrant seeds), and doesn't leave any residue.

No, but it won't help - I do use household bleach on seeds (including
ones that have already sprouted) to kill surface mould, and it doesn't
seem to affect plants significantly. Chemicals won't do the job; only
steam would.


Regards,
Nick Maclaren.

I have posted here before to say Microwave the soil.
If you seive your soil/compost then fill a 2 litre casserole dish with
it, put the lid on and microwave it for about 8 to do mins, making sure
the soil goes in damp.
I bought a cheap microwave that |I could use in an out building as not
everyone likes the smell off cooking soil.
It's supprising how much you can do in an hour.
You can then mix it with coir or what ever you want as well as pearlite
and or sand, gravel and a compost base mix.