I can't find info on my soil series (Timonium, MD) but is super hard (we broke a hoe making the SFG bed.) When it came time to put up the trellis, it seemed almost impossible. Then my non-gardening spouse came up with the idea of using shepherd's hooks topped with fencing posts. We set a hook at opposite ends of the rows needing support, wired down the fence posts, which fit nicely in the hooks, then tied on strings for the plants! -- What looked like eight hours of back breaking labor in the sun was dropped to only two!

Hope this helps someone with really hard soil problems. It was not hard to bang the 6 - 8" deep spikes of the hooks into the earth with a sledge hammer (large axe would also likely work.)

BTW, we augmented this blasted soil with compost and Miracle-Gro Soil (sorry, I'm not a completely organic farmer.) I'm open to other suggestions.

Hardclay