A sycamore is nobody’s first choice of a tree for a small garden. It’s messy in spring with drifts of pollen and the detritus of flowering. Then comes the sticky deposit of aphids and deep summer shade. The autumn leaves, curling and brown, form useless piles; and far worse are the seeds, obscenely fertile, germinating like grass in every chink of soil.
But we have a big one, seven feet round and fifty high, and no seedlings. Come to that, no flowers. We respect it like a London plane, light up its peeling trunk at night, and suffer its shade – if not gladly, at least patiently. What’s the trick?.
See if you can understand this account of its sex life. “Most inflorescences are formed of a mixture of functionally male and functionally female flowers. On any one tree, one or other of these flower types opens first and the other type opens later. Some trees may be male-starters in one year and female-starters in another. The change from one sex to the other may take place on different dates in different parts of the crown, and different trees in any one population may come into bloom over the course of several weeks.” (This comes from Wikipedia).
Part of the answer is in its fashionable hesitation about its gender. If only it would decide to be a boy how happy we would be. But the main reason it lacks a sex life is that we prune its shoots back brutally every winter to limit its spread over other people’s gardens (and our own). I suspect its wood never ripens enough to get to the flowering stage. It’s an expensive solution.