amended clay is ok for nantes, chantenay and danvers 1/2 long types. they are thicker and stockier and can push htrough it. you'll get better results if you make sure there aren't any rocks or large lumps in the clay, though. you could try digging a trench and filling it with sand mixed with some screened soil. i've grown them for yrs in my amended clay(never tried the trench thing, just read about it), and while they aren't beautiful, they do grow fine and are edible. sometimes the roots make the most fantastic shapes if they hit a rock. there's a winter verggie thread a few down that has some gorgeous photos w/carrots- ask them how they did theirs. tammy