Snow wrote (see)
I learned this the other day.
They say not to eat blackberries after Michaelmas day.....29th September as they'll be bitter. Folklore said as Lucifer was chucked out of heaven he was so angry he spat on them as he fell from grace....
I heard that he did something even more unpleasant than that on the other hand the more polite people say 'he trailed his coat-tails over them'.
Other ones from my childhood were never to have lilac blossom in the house, and never to have red and white flowers in the same vase together = blood and bandages.