I have never used a Cactus mix. I use a Fafard 2 mix. If I ever amend the soil I always mix 50/50 mix with the soil I dug the hole from. It all depends on your soil conditions. At that price I would throw them in the ground. They grow like weeds here in Florida. Occasionally after the rainy season it does not hurt to give them some fertilizer with some Maganese in it as sometimes the Pygmys like to get the frizzle top look. I prefer not even trimming them myself but everyone has different strokes. Again California growing is much different then Florida so my advice is based on what happens here.
