How much dirt to buy....

Site is 1/2-3/4 mile from road.. rough terrain getting in.


Native soil doesnt seem to promising. Partner and i plan to carry in some cheap topsoil from the depot. (yes going to add fert/perlite etc)


The question is how many bags to buy?

Growing in large 15gal pots.


The topsoil comes in 40lb bags.

Any guesses on how many pounds of dirt per gallon? This would be extremely helpful tomorrow morning at the garden place.

I use sungrows grow mix 4, you can get um in huge bales for like $25 a bale I say it wuld fill about 3 15gal pots when broken down it has peat, perlite, lime, and other good stuff. Works great...

What about buying & carrying in compost.. ,mix with the soil you have, then amend with perlite & ferts?