Jai_Ganesha said:Do you use the chunky or the fine kind (or both)?
I use the chunky coir for mulch (helps a lot with moisture retention) and the fine coir for potting soil. Some people will use the chunky kind for soil (in big pots) because it traps a lot of air and does not compact. I have not had the need, and the ground product is much easier to work with when I'm potting up plants.
I'm a big fan of a universal mix for all succulents, pretty much from day one. If that's the direction you want to go, consider 3 things.
1. Compost breaks down over time and will turn into dust after a year or two, longer if it's the chunky, barky type. When you choose this organic part of your mix, be aware of its short lifespan (some types shorter than others) and the need for regular repotting to replace it, unless you want to rely on a more durable fiber like coir or peat.
2. Just as important as the actual ingredients are the particle sizes. You generally want to avoid fine ingredients. This applies to the coir/peat, which tends to compact into a brick when given the chance. It's best if you can see the actual fibers. And it applies to the aggregate (pumice/whatever), where you will generally benefit from passing the source material over a fine screen (window screen works) before adding it to the soil. It does not matter so much with the compost, but ideally a chunky type is best there too. The only exception to this rule is when you are sowing fine seeds, in which case you might use a finer grade of rock.
3. The most important thing to be consistent about (if you have to pick one thing) is the ratio of organic material to rock. I like an equal mix (which turns into 75% rock over time, after maybe a year or two, as the compost breaks down). You might vary this ratio, all other things equal, in order to best avoid problems with rot-prone plants. The soil will dry out faster with more rock. But I have found that careful attention to exposure and the judicious use of unglazed clay pots more or less circumvents any need to adjust the mix.
