Answer: It's not likely that dropping pine needles or low soil pH caused the disappearance of your broccoli leaves. Slugs and snails are voracious nocturnal eaters, so you wouldn't normally see them feeding, but they do leave a slime trail. The probable culprit is the Imported Cabbage Worm. These are the larvae of a small butterfly (white wings, edged with black and one black dot on each wing). The larvae feed exclusively on cole crops. If you haven't had them visit your garden in the past, consider yourself lucky! The plants may recover, so wait a week to see if any new sprouts appear. If not, remove and replant. You can avoid this problem in the future by using a floating row cover (like Reemay) over your seed bed to exclude the adults and keep them from laying eggs near your crops. Broccoli doesn't need to be pollinated, so you can leave the cover on until you harvest.
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