Why does my Christmas cactus only have flowers around the edge?
Margaret Kirby, Pickering
Stefan says: It’s my view that the Christmas cactus Schlumbergera truncata, and the Easter cactus, Hatiora gaertneri, have either forgotten about the seasons, or have become totally confused, because I regularly see them in flower at the ‘wrong’ times of the year. Your plant seems to have more or less the right idea because it has a wonderful display of flowers around the edge now; but the problem has been with those in the centre that have dropped off.
You mention that it hasn’t been moved or disturbed, and I assume you say this because you have read that moving the plant will cause problems. I think this is an urban myth because I’ve never known that to cause trouble. But I believe the situation with yours is that the centre of the plant has started to deteriorate with age and/or it’s dry and impoverished.
Stefan says: What an extraordinary find to turn up among some weeds! Obviously a bird must have acquired the seed from somewhere and dropped it. It’s Hyoscyamus albus, the white henbane. It isn’t a garden plant and originates in southern Europe but is seen occasionally in herbaceous borders, although it’s an annual or sometimes biennial.
It does have a native relative, albeit a fairly rare one, in the common henbane, Hyoscyamus niger. Both belong to the potato family, the Solanaceae and like so many other plants in the same family, they’re extremely poisonous. They contain toxic alkaloids, which have a wide range of serious effects. Like many other poisonous plants, some of the chemicals do have medicinal properties and one of them, hyoscyamine, has been used widely as a treatment for migraine. But under no circumstances should you ever try any home-made remedies made from parts of henbane plants.