A: The potting media that I use often-times depends on the species that I am transplanting. If I am transplanting bananas for example, I would use a common potting or planter mix available at any nursery or soil yard and perhaps add 10% organic compost.
If I was transplanting papayas, I would use a potting soil that allows for very good water drainage such as 50% “Cactus Mix” and 50% #3 perlite. Depending on the species, some plants are more susceptible to Phytophthora cinnamomi ( ROOT ROT ) than others and as a result, certain precautions are warranted such as the use of a “Good” draining potting soil which has been proven to suppress this disease.
There is not enough space here to properly address this topic, so I will only offer two basic potting mixes that have worked well for me in the past. The first mix consists of 50% Supersoil brand Cactus&Palm Mix(Available at Home Depot), 25% 3/16″-1/4″ size pumice and 25% screened #12 coarse sand(Available at Orange Co. Farm Supply). I use that mix as a general purpose mix for more common fruit trees such as citrus and avocados.
This second mix I use for the more rare and/or delicate tropical fruit trees such as jackfruit, green sapote, sapodilla, mango, mamey sapote, star apple and wax jambu. It consists of 50% coir chips(1/4″ – 1/2″ screened uniform particle size),25% 3/16″ – 1/4″ pumice,12.5% peatmoss and 12.5% organic compost ( Try “Gardner&Bloom).The basic idea here, is to have a mix that has very good water drainage (High air-filled porosity) and good water retaining capacity at the same time. This can be achieved with a “balanced” mix( Like the one above) that has relatively large and small particles which in turn offers the proper ratio of solids to pore space so that there will be enough water, air and structure for the roots to grow onto and through while at the same time suppressing P.cinnamomi.
Please keep in mind that most sands do not offer “good” enough water drainage for tropical fruit trees in a container because of the high percentage of fine particles resulting in very small pore spaces thereby reducing the rate (Poor Drainage) water moves through a medium ( Infiltration rate). That is why I specified the exact product to be used as a sand which should not be substituted with a common sand. Please feel welcome to contact me for clarification regarding the above suggestions.