I wish we could use the dirt here, but it's very poor soil and VERY rocky. Including boulders the size of cars and bigger. Glaciers, dontcha know. Tilling that stuff up is an impossibility. So we have to buy our dirt. We're such bad gardeners, we've found it pays off to buy the expensive fancy dirt with the fertilizer already in it, plus the mulch, compost, etc. already mixed in the proper quantities. We've mixed our own many times in the past and it's never worked, even with the advice of master gardeners. I envy those with better gardening skills than we have, and who have natural materials to work with, like we had in southern Minnesota farm country where I grew up.