i have taking all nets off as the stuff grew too large. might protect some of my greens when there is not much about later in the season - cheers for that thought.
i was lucky with the cabbage white butterflies - they didnt like to lay eggs close to dill (euch, that stinks!) so ended up laying on my nasturtiums, which was fine by me. even easier to spot the larvae on the smooth round leaves of a nasturtium than on the jagged leaves of brassicas.
now, what i want to know is when do the whitefly die????!!!!!