I made a custom cacti soil mix for succulent, which is 1:2:1:1 of potting soil, pumice/perlite, coir and fine vermiculite.
I think it should be quite loose, should I add gravel?
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Sign up to join this communityI made a custom cacti soil mix for succulent, which is 1:2:1:1 of potting soil, pumice/perlite, coir and fine vermiculite.
I think it should be quite loose, should I add gravel?
Soil mixes are a topic that has many opinions. Some common tips are not as good for a plant as you might think.
For the soil mix you mention the components that degrade are the potting soil, which is probably peat based, the coir which slowly breaks down and the vermiculite. If you do not intend to repot the plants on a regular basis a soil mix that would last longer could incorporate some portion of a clay based soil. One recipe calls for:
1 part garden soil 1 part coarse builder’s sand 1 part peat moss
Notice the use of sand, usually clean sharp washed sand to improve drainage. Your mix uses perlite and vermiculite to improve drainage.
Try your mix out and see which plants do better in it but don't bother with gravel or clay shards.
You really want to match the potting mix to the natural habitat of the plant you are growing and to your watering habits. Some growers go with completely inorganic pumice or fired clay mixes for things like haworthia and gasterias and water more frequently and with special fertilizers.
If you use sand make sure it is not Builder's sand which is a type of sand that is supposed to compact down. You need sharp sand. These are two different things. Builder's sand will pack hard and eventually result in root death because roots need oxygen and the sand density will suffocate them.
An excellent and cheap additive for succulent potting mixes is Napa Auto Parts Oil Dry #8822. This is a porous fired clay that doesn't break down or clump.
Yes, please. The ground already prepared is generally good. In my opinion, I would add some clay to the mixture.
But, for excellent drainage, you have to put on the bottom of the vessel a shard of broken pot for each hole of drainage. And, in addition, about half a centimeter/1 cm of gravel on the bottom. Depending on how big the pot is (and the plant, of course). Don't mix the gravel with the soil.
Use a new pot, or an old one, thoroughly disinfected.
For disinfecting clay or gravel, or pot if you are not sure, use hot steam, by a machine steam or an iron steam.