ralphrmartin wrote: ↑Sat Oct 13, 2018 4:58 pm
Interesting Nick. So how do you stop everything growing fungi and rotting off in the humid conditions used for seedlings? Do you sterilise your mix somehow before sowing the seeds?
Like Nick I use a JI mix to sow seedlings (in fact just my standard cactus mix of JI, grit and moler clay). Very rarely have any problems with rotting/fungi etc despite leaving pots in a propagator standing in water for the first 12 months. I occasionally get a bit of moss, but the seedlings seem to outgrow it ok eventually. The only time I ever attempt to sterilise the compost if if I sow very slow-growing cacti with tiny seed like blossfeldia/aztekium.
ralphrmartin wrote: ↑Fri Oct 12, 2018 7:52 pm
Maybe more carbon is available?
Probably light levels and a burst of nutrients from repotting (carbon is coming from the air I think)
ralphrmartin wrote: ↑Sat Oct 13, 2018 4:58 pm
Interesting Nick. So how do you stop everything growing fungi and rotting off in the humid conditions used for seedlings? Do you sterilise your mix somehow before sowing the seeds?
My mix has quite a bit of sand in it, and the vermiculite fairly quickly turns to mush, which presumably gives the roots more chance than the larger particles of cat litter.
Nevertheless, your observation about roots could well be why my seedlings take off when transplanted...
I microwave the compost for a couple of minutes and spray the seeds and top of the compost in the pot with 6% hydrogen peroxide straight out of the bottle. Not really necessary but it does no harm.
BCSS no.33806
Turbinicarpus, Lophophora, Ariocarpus, Lobivia and Gymnocalycium
ralphrmartin wrote: ↑Fri Oct 12, 2018 7:52 pm
Probably light levels and a burst of nutrients from repotting (carbon is coming from the air I think)
It's not intrinsically a burst of nutrients, as every day I spray the seedlings with a solution of fertiliser. Of course, it could be extra nutrients becoming available with rapid root development allowing more uptake.
I also doubt it is the extra light - my propagaotr is on top of the bench, so the only difference is whatever is filtered out by the polycarbonate top. My seedlings are in a much brighter place in practice than most people's, from what I have seen when visiting other collections.