I am interested in using low or no peat in my normal soil mix. I am looking for blends that are working for others. I got back into keeping C&S after 20 years of absence, and soils have changed a good bit. Currently, I am working with a mix about 30% potting soil, 30% pumice, 20% builders sand, and 20% charcoal. Is a mix like 50% pumice, 30% sand and 20% charcoal, feasable? Builders sand is a coarse to fine sand, with 10-20% silt or so. Its easy to get and cheap around here.
the growing medium really depends on what kind of plants you're going to be growing. some cacti do better in sand/pumice/soil/charcoal and others do better in rock/sand/charcoal and very little soil. most succulent types (other than cacti) will do fine in the mix you are currently using. things like hoya, epis, philodendron and bromeliads do best in bark/charcoal/compost. i don't know if i'd use builders sand or not...they do sell sand specifically for using with plants... what particular plants do you have/want? that's really the key to what growing medium should be used for best results.
Mostly the plants I am thinking about putting on a peatless mix are Lithops, Pleiosplios, and Titanopsis, Luchenbergia. I wonder about soils for Adromischus, Haworthia, Pelargonium, Uncarina and Aeonium. They seem to do well with pretty high peat based mixes, but could they do better up here with non peat mixes.
One caution with builders' sand - rinse it with plenty of water a couple of times before use, in case it has a high salt concentration.
The builders sand around here is from sand pits during the glaciation, I know of no mining of areas where the material would be salty. BTW, I am a geologist who is typically having to work in the building industry, so I know about where materials come from, and what's in them locally. I use builders sand, as the stuff I can find commercially for plants is extremely fine and I have read about using coarser materials. One of the mixes I am interested in is making a bit of Steve Hammer's mabel-mix: two parts loam, one part coarse sand, one part pumice. For more elaboration on mabel-mix and on keeping mesembs, see http://homepages.nyu.edu/~ms689/AGM.html Loam is a blend of clay, silt and sand which is quite common for those of us in glaciated terrains. for further elaboration: http://nesoil.com/properties/texture/sld005.htm On mable-mix, my only goal is to keep my Titanopsis on it, as Hammer is quite enthusiastic about how it works.
Depends on where you are. Around here, a lot of sand used to be mined off coastal beaches and was salty. Fortunately that's been stopped now as removing the sand was increasing coastal erosion - but it was a 20 year battle with the mining company to get them to stop.
Yep, I hear you. I guess we can thank the glaciers for providing such good sand and amazing amounts of it in our area.
