Glad to see some folks with an interest in the grow bags. One of the biggest concerns is the cost of filling the bags.
Its true that it can be expensive, at first. I have no reservations with recycling soil. None what so ever. Another point, at least for me is a native soil drainage issue.
Now onto the cost..
Locally I buy my products. I purchase my ingredients and mix my own. I use 3 parts peat to 1 part perlite, plus lime.
$11 3 cu.ft. peat moss (need 2 of those)
$18 4 cu.ft. perlite
$? Lime (arguably cheap, and it lasts for ever.)
So thats $40 plus the lime.
The peat moss should expand by a factor of 2. So 2 bales should expand to approx. 12 cu.ft. Add in 4 cu.ft. of perlite. Thats 16 cubic feet of soil, give or take.
16 cubic feet of potting soil should equal approx. 102 gallons. My 7 gallon bags realistically hold 5 gallons of soil. 102/5=20.4.. So we should be able to fill 20 bags for $40. 40/20=2.
So, each bag should cost about $2 to fill with a basic potting soil mix. With all that being said I have been trying out different combinations, including adding compost to the mix. I havent done the math on using compost, I just happen to have a small mountain left over from last year.
