I've done that method, dig and then use a spading fork to break up the clay/hardpan below. I just can't do it anymore, too much arthritis.Good point. I had a really heavy clay base in the mid Atlantic US, but not too many stones. Instead of double digging -- once I signed off on doing so much hard work -- I would dig to one spade length, take out the soil, and gently open the clay base with the tines of a pitchfork, rocking it with my body weight to loosen it up a bit. Then I'd layer in the soil I took out with compost, aged horse manure, a bit of broken up lime mortar from an old outdoor fireplace -- I was more of a forager than a shopper when it came to finding garden amendments. My idea of productivity is "How much is this producing relative to how much effort/$/time I put into it?" I wasn't relying on selling the output, so as long as I had something fresh to eat every day, I would sacrifice a bit of productivity to be satisfied with less work and just using free stuff.
When we first moved to South Carolina in the 1980s we discovered the soil was red clay, much of it hard, "adobe brick" as my dh said. It was nearly impossible to dig, bent my spading fork trying. A regular rototiller would bounce off the ground, and it took a big tiller (Troybilt Pony) we borrowed from a friend to loosen up the dirt to start a garden.
We managed to hand dig small holes next to our rented mobile home, then we added pureed watermelon rinds and other fruit/vegetable scraps. Within a fairly short time I was able to plant some flowers in those spots!
Last edited: