Sterilising seed compost

[David_L]

Hi Susanne

No ordinary cactus mix from gardens centres isn't great for seed raising, in fact it isn't great full stop, though some acid lovers like Gymnocalycium and Rebutia like it well enough. For seed raising John Innes seed compost is best as a base, with any large bits sieved out then add an equal volume of seed grade vermiculite which most garden centres stock. Simple and it'll work fine for most things; yes you can replace part of the vermiculite with grit or perlite or Tesco's Premium cat litter or other fancy stuff, but the simple recipe does work.

[iann]

Moss grows from spores which are tiny enough to blow about in the air everywhere. One falls on your sterilised soil before you cover it and you'll probably get a colony of moss.

[Julie]

Roy - I will remember that tip for potentially irate mothers too!

So.. how to sterilise a seed? Would a little Provado solution sort out the yuckies? Or is Chinosol/Cheshunt the only chemicals that are safe for a seed or seedling?

I guess moss and so on can be reduced by doing things indoors or in a greenhouse at least?

As for neem, I have used it on my skin, but.. not for bug killing. Not a bad idea, has anyone else experiemnted with it? It sounds a nice organic eco-friendly option - if it works.

Hydrogen peroxide?? This would presumably benefit by killing everything but the seed.. being an oxidant it should work like bleach on the microscopics (without giving off stinky chlorine), or just giving off oxygen as it breaks down. Presumably not enough to prevent enough CO2 reaching the seedling surface.

What we need is a volunteer with many, not too precious, identical seeds. Bagged trays with all the different potential anti-nasty agents in... and see how they grow.

[Bill]

As it happens Roy, I may actually be getting an small autoclave in the spring, thier use in theatres are frowned upon nowadays, so when the ophthalmology theatre is refurbiushed in the spring, I have asked about buying the one from there, got a little project in mind for but it will come in handy for soil LOL

[Cactus Jack]

Do you ever wonder how a seed manages to grow in the wild without all this intervention? Lol. )

[Julie]

Jack, I thought that!!

But I guess they are more spread out in the wild, so the nasties can't get a grip of a whole batch of seeds....?

[iann]

Not many fungi in the Atacama desert

[Vic]

Plenty of spore forming saprobes though being dispersed by wind.

[iann]

The best thing about saprobes is they won't rot cactus seedlings