There are many ways to make a successful potting mix and some great recipes out there. This is the basic mix that we use for large quantities of cuttings. For smaller batches Pro-Mix HP or any potting soil made for houseplants is a good place to start. Mixing some extra perlite or vermiculite with potting mix you buy in the big box stores is a good idea too to make sure your mix is light and not compact. Here is the recipe we use.
Our mix is 50% Coco Coir. Coco Coir is a renewable alternative to peat moss it is similarly priced and works about the same as peat moss. The other 50% is perlite, vermiculite, or Parboiled Rich Hulls (PBH). Perlite and vermiculite are mined minerals that are heated to expand and ‘pop’ to be light weight water retentive materials. PBH is a byproduct of rice processing and is available more cheaply in some places. This article covers perlite. We also add dilute (half strength) Miracle Grow for potting mixes intended for cuttings. We generally stick to organic practices and products, but chemical fertilizers offer some energy to cuttings without introducing smells or sources of mold. For potting mixes intended for outdoor plants we add organic fertilizers to the top of the pot once the plant is potted up. We also add Gnatrol to every mix to help reduce the chances of fungus gnat infections. This is only necessary if you have started to notice fungus gnats.
Reconstitute the Coir
Reconstitute the coir by making a mix of water, Miracle Grow, and Gnatrol. Miracle grow should be 1/2 tsp per gallon and gnatrol is per the instructions. We use between 6 and 8 gallons of water to reconstitute an 11 pound block of coir. The coir can be soaked in the water mix, and/or you can pour the mix over the coir block.
Add the Perlite
Mix the coir up to remove any dry spots. We then stack it up on one side so it is easy to measure out an equivalent 50% of perlite.
Last step is to mix it all up. Mixing by hand is an easy way to get a good mixture of perlite and coir. The end result should look something like this.