Here’s yet another long-held belief that new data says is false.
QUESTION: This spring I planted brassicas, and so far the deer don’t seem to be eating them. Someone told me they don’t eat them until frost hits and the starches turn to sugar. Is that true?
ANSWER: For a long time, it was believed that after a hard frost the starch in brassicas (rape, kale, turnips) would turn to sugar, making them sweeter and more palatable, and therefore more attractive to deer. However, recent research has shown that’s not the case. In fact, starch levels in some species (kale and radish) were higher post-frost, and simple sugars remained about the same.
That being said, I’ve observed the phenomenon often enough that it’s not mere coincidence that deer suddenly and dramatically turn on to brassicas – barely eating them before the first killing frost and then chewing them down to the stem in a few days. Obviously something changes.
If it’s not an agricultural area, it may take deer time to discover what brassicas are and that they’re edible and nutritious. That still doesn’t account for the sudden, dramatic shift, though.
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