1part standard poting soil
2parts of pumice. Pumice (volcanic rock)that is porous. Substitutes include pearlite, non-soluble cat litter, aquatic plant soil or Turface, NAPA oil dry #8822
perhaps 60% pummice/grit/litter to 40% potting soil.
use 1 bucket (or 1 part) of coir in my mix....
for epi:
1part standard poting soil
1parts of pumice
2parts coarse "orchid bark". This is ground up redwood bark pieces that are marketed for use by orchid growers
Info From KADAS GARDEN:
Mineral Mixes
These mixes are intended for good drainage, and fast drying times. This is useful for species that are from dry areas, have large taproots, and are slow growing. Some examples: Ariocarpus, Astrophytum, Aztekium, Echinocactus, Lophophora, Obregonia, Turbinicarpus etc.
30-60% Grit
10-30% Pumice/Perlite
10-20% Coarse Sand
5% Slow Release/Pellet fertilizer (optional)
For Water tolerant species
For water tolerant species protected from the rain/uncontrolled water. useful for plants such as: Cereus, Echinopsis, Harrisia, Myrtillocactus, Neobuxbaumia, Opuntia, Polaskia, Rebutia, Stenocereus, Trichocereus etc.
30-50% Coco coir/Peat/Top soil
10-20% Pumice/Perlite
20-40% Grit & Sand
In our greenhouse we use a 60% Coir, 30% grit, 5% pumice & 5% organic pellet fertilizer for all columnar/water tolerant species. Keep in mind in a greenhouse, people control the water.
For Tropical species
This mix is useful for tropical species that tolerate, and even prefer moist/rich soils. Some examples: Acanthocereus, Hylocereus, Pereskia, Pereskiopsis, Rhipsalis, Selenicereus etc.
70% Coco/Peat/Top soil
10% Grit/Sand
10-20% Compost
5-10% Manure/fertilizer
