's perfect potting medium:
1 bushel sharp sand
1 bushel clay loam
1 bushel pro-mix or a balanced compost
3 cups epsom salt
3 cups coffee grounds
3 dozen egg shells
Make sure that the pro mix you use has sufficient organic content to ensure adequate drainage. Perlite and vermiculite are good for drainage, but contribute nothing to the organic content. Peat moss or coconut fibers are better. Worm castings and bat guano have good nutrients, but don’t help drainage. Making your own compost is best.
The sharp sand is heavy for containers, but I’m trying to reproduce an optimal soil, based on the average content of good soil.
Unlike other super-soils all the amendments are long term and won’t burn delicate babies. Hey, your payin an arm and a leg for that coffee, use it twice. Watch the pH.
Before you plant anything in it, bring it to life by watering with a solution you make by putting the following into twenty gallons of water:
1 can beer (enzymes)
1 cup soap (helps wet soil)
1 cup mouthwash (protects seedlings from damping-off)
1 t instant tea powder
1/2 cup corn syrup
1 T B1
A couple dashes of H2O2 will eliminate Cl in tap water