You can mix about 80% sphagnum peat with any potting mix. Sometimes I make my own mix, 70 sphagnum peat, 20 perlite 10 vermiculite is fairly typical but not cast in stone. As long as you don't add sand, manure, and/or compost as they will all impede wicking. Before I knew there were "recipes" I grew my tomatoes in straight sphagnum peat and they did fine.
|