Germination mix

What germination mix for alpines are you experts using?
Do you cover the seeds with grit?

I understand John Innes compost is great, but can not find in USA.

Thank you,

Corinne

Corinne, I've used everything from promix to pure sand. I mostly use promix with extra sand and some turface. Fine seed I do not cover but I do cover the pot in saran wrap until the seeds sprout. larger seeds are either covered in the soil mix or sometimes I used fine grit. Budgie bird gravel works well as it allows light to reach the seeds and most alpines seem to need light to germinate.

what is the composition of promix?

Todd, thank you for the info.

I have horticultural sand which I have added to Plantation Seed Starter; also have and used Gardeners Supply products. They seem to do the job. I thought perhaps
there is something better.

Budgie bird gravel? Where do I find that? I have pea size gravel on hand.
Will that do?

Corinne

I have an entire sack of chick grit that I had planned to use. I hope it is fine enough.

Another question -- in several places discussing germination of alpines, people have described sanitizing the soil by pouring boiling water over the pots before planting. Does this work?

I've never bothered with that sterilization process. Typically the mixes you buy are already
sterile. And I use chick starter grit - is this what you have?

Tam

I *do* bother with the sterilization process. The weather here is very unpredictible, and I have had problems with various kinds of damping off etc. in plants on my patio. Ordinarily I use a drench of physan when first wetting down the planting medium, regardless of origin. Boiling water would be a huge pain, but if it works better I am willing to try it.

Well - at my NARGS chapter meeting last year, Jim McClements described how he starts
ferns. He sterilizes his soil by thoroughly moisening the soil, places it in a baggy and then
places it in the microwave on high for 20min. This completely sterilizes it for the fern spores
and I would think would work for your purposes as well.

Tam

It might. I have done something similar (in the oven) for soilless mix for my rose cuttings. I am starting several thousand plants just now, and I would be microwaving constantly between now and next march if I did that. I think I will take my chances with my current method using physan drench.

Have you tried hydrogen peroxide? I've seen folks swear by it on the seed starting thread.
I tried it last year but haven't had enough trouble with damping off to say much one way or
the other about it.
Tam

I've never used hydrogen peroxide on alpines but I guess it could work. Typically I use hydrogen peroxide on daylilies and iris.

Budgie gravel is available in pet stores but chicken grit works well too. Promix is peat and perlite mix so is soilless. I have had bad damping off with soil-based medias.

I think promix is comparable to the soilless mixes we have available here. I always add chicken grit and/or vermiculite for anything that will be sitting outdoors, and vermiculite to anything under lights indoors. I have ocassionally used peroxide on my rose cuttings, but with mixed results. Physan works better for me, esp. in the winter.