There are at least three qualities that your vegetable growing soil must possess.
1. Soil must drain well and allow for oxygen to permeate.
2. Soil must hold moisture.
3. Soil must contain nutrients.
The first two seem to contradict each other…but if you think of how a sponge works, maybe it will seem a little less contradictive. You basically want your soil to behave like a sponge holding both air and water.
For my raised beds, we used a mixture of 1 part peat moss, 1 part coarse sand, and one part compost. The compost I used was ‘composted cow manure’ from Menards. This compost had quite a bit of clay in it…which wasn’t a bad thing, because clay contains lots of minerals. If I had it to do over again, I would have used two different kinds of compost…like the mushroom compost they sell at Home Depot along with the composted cow manure from Menards.
Because compost, which was the nutrient component of my soil mix, also helps retain moisture, I would have added more of it to my mix. In the future, when I am mixing new soil for raised beds or pots, I will use 2 parts compost, 1 part peat, and 1 part sand.
The year before, I used a mixture of 1 part top soil, and 1 part composted cow manure. It made a very heavy soil, one that I would NEVER use in a pot…but it grew absolutely huge bell pepper plants in a raised bed box.
I added a little organic fertilizer to the mix for potting up the plants I sold this year.
If I could have done that over again, I would have left out the bone meal entirely. The potatoes my son and I planted in the long bed seem to love the bone meal, but the seedlings would have been better off without it. I too could have done without my greenhouse smelling like I buried my enemies in there. YUCK!
My advice regarding bone meal is to use sparingly and mix into the soil very well.
I found lots of recipes for potting soils on the internet that get specific in regard to ingredients and additives based on what you intend on growing in it. I suppose anything can be complicated if you want it to be.
If you just want to make lots of inexpensive soil for a raised bed garden, my mix will work just fine. I urge you to use a 5 gallon bucket to measure, and peat moss fluffs up quite a bit so the 2 cubic foot bale makes a lot more than you’ll think it will.
Dump the 5 gallon buckets of each ingredient on a tarp, and use the tarp to mix by pulling the mix over on itself. Lay thin layers of the mix into the bed and water as you go. Peat moss has this way about it…and if you don’t water as you go, you’ll have a heck of a time getting the soil uniformly and completely wet.
Soon, I will need soil for my rain gutter grow system . We will be moving before harvest, so mobility will be a factor. Since I need the soil for the grow system bucket to be lighter than what is/was in my raised beds (or my smaller pots that I don’t want to blow over in the wind), I will use vermiculite and/or perlite instead of sand.
I’ll keep you posted how all that goes!