Kim Wilde answers your gardening questions.
Every spring, and throughout summer, a huge number of enormous spiders decamp to my back garden in London. They weave webs in the evergreen trees and colonise the larger plants (all of which are in pots). They seem to be all of one kind: stripy and very large, and they bite. Could you advise me on how to get rid of them?
The spiders might be Argiope bruennichi, the yellow-and-black-banded wasp spider, which is increasing in southern counties, perhaps due to climate change. However, they do not mature until late summer, and if they are there already they would be only spiderlings. Also, they are not known to be biters. Most other of our larger species, such as the very common garden spider Araneus diadematu s, are also mid-to-late summer maturing; very few of them bite humans. Spiders do an excellent job in helping to control insect numbers - they really are man's best friend, and I would recommend you let them get on with it and keep out of their way.
I had a healthy Aeonium arboreum before I moved house. Now all the leaves have fallen off (it's bald) and one stem has drooped. What is wrong with it, and how can I revive it?
There are around 30 species of these beautiful succulents, which thrive in gritty, free-draining compost and partial shade. Christopher Lloyd remarks that these rosette-shaped plants look as though they can receive signals from outer space, and, interestingly, that they sometimes wilt in the sun. They prefer filtered light, and compost should be allowed to dry out between watering, although since they are not truly drought-tolerant they respond well to a drink in very dry conditions.
Sudden leaf fall without a prolonged preliminary period of wilting or discoloration is generally the result of a shock to the plant's system. Perhaps when you moved, there was a dramatic drop or rise in temperature, or a sudden increase in daytime light intensity, or even a strong, cold draught. If the plant is 13-15cm high, cut through the middle, and the remaining stump should branch.