I did one of my big plots last year with PTT, GHR, and crimson clover. I let the clover grow till it was about past full bloom and tilled it under friday. It got shaded out a bit by the brassica in the fall but you could tell it was there, and once spring hit the clover took off. It was by no means a full stand but it was there. Would I do it again? sure would, will be planting the same mix with the addition of some yellow mangels as well.