Is it possible to use all peat moss for WS? It's all I have right now so thought I'd ask. Thanks
No, bad idea. Straight peat will become hydrophobic if allowed to dry out, you almost have to use hot water and stir or knead it in to rewet it - which you can't do of course with seeds sown on top. You'll be happier and so will your seedlings if you wait until you can pick up some potting mix/potting soil.
OK will do. Thanks
ProMix is peat mixed with perlite. I could be wrong but I think most all seed-starting mixes are mostly peat moss. Potting soil is used once seedlings are up and growing. Once the seedlings use up the nutrition in the seed, they need something like compost which will be found in potting mixes.
A compressed bale of peat moss is very inexpensive. All you need to do is mix it with a bag of perlite or vermiculite (to lighten it up) and you have the equivalent of ProMix if it isn't available in your area.
Personally, I buy the compressed bales of ProMix because I find it easier than doing the mixing thing. Once I am ready to transplant my seedlings, I add compost from my working compost pile to the ProMix and I have 'potting soil'.
To make your own peat based potting mix in addition to perlite or vermiculite, you would also normally need to use some lime since peat moss is acidic. Commercial mixes also often include a starter fertilizer and a wetting agent that makes it easier to get the peat moss wet. If I recall dish soap has a similar effect for wetting? There are some recipes over on the container forum.
I buy potting mix for wintersowing for convenience, but make my own mix for container planting. It is the 5-1-1 mix (from container forum) and much cheaper and better performing than regular potting mix.
Can't get the ProMix here, but the online label shows Canadian Sphagnum peat moss (65-75 % / volume)
Perlite horticultural grade
Dolomitic and Calcitic limestone (pH adjuster)
+ The ingredient that helps to solve the water repelling tendency of peat = a Wetting Agent
And some of the product line, not sure if all, Mycorrhizae fungi
I don't mix my own, but one of our local Mom/Pop garden centers does mix and bag potting soil for us, using the Cornell 'Peat Lite' recipe and tweaking it a little for this mild wet climate. I'm working towards more in the ground and covered by sprinkling system (system that still needs an overhaul), and less in containers dependent on me, so am using less potting 'soils' these days ;)
If you buy dry peat and use it wear a dust and particle mask while doing so.
In the last decade of my life - never used a dust mask -- good idea not to inhale it though.