here's my recipe.
2 parts premium top soil
2 parts premium composted cow manure
1 part potting mix (whatever kind)
2-4 hand shovels of vermiculite per 5 gal.
4-8 hand shovels of perlite per 5 gal.
a good handful of dolomitic lime per 5 gal.
the vermiculite and perlite go in "as needed", so does the lime. if your potting mix label says it comes with peat moss or pine compost it will have a low pH so maybe add more lime. vermiculite adds texture to the soil, makes it breathable because it expands/contracts when it gets wet/dry and you do not want too much in your mix because it holds moisture very well. perlite helps keep the soil from getting too compacted from heavy rains and this helps the roots breath.
you don't need designer dirt, just go to your lowe's or HD and get some of this stuff, you won't be disappointed!
good luck.
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