Had what I thought was a polyanthus in a pot which was definitely not thriving. Lifted it and transplanted into the garden with some good compost. Now have a foxglove over a foot high. Isn't nature wonderful.
I remember, someone who had been trying everything to try to get their blueberry to bear fruit.
To cut a long story short, they had been trying to get a self-seeded goat willow to harvest some blueberries, which had taken over the pot. The original plant had long since died off.