while identifying what the grub was in my cabbage roots I read that the cabbage root fly grub eats the main root of radish,swede and turnip also the roots of alysumm,aubrietias,stocks and wallflowers as they are all members of the brassica family. to help prevent it earlier in the season it says to cut down hedge parsly before it flowers as the flies feed on it before laying eggs
from whats wrong with my plant by steven bradley
marg