I am seeding cover crop in now of oil seed radish, clovers and oats everywhere but next year's brassica/cabbage plot(will get just clover later). I have broccoli and cauliflower still growing from spring in an area that will be squash/melons/lettuce next year. Should I pull them or leave them in, or maybe leave roots in to rot? Soil in that plot is clay/gravel with amendments made this year. I haven't had any disease within the plot.

Any ideas?