ASK MONTY

Q I have an aeonium that’s top-heavy and difficult to manage. How should I deal with it? A Aeoniums are surprisingly hardy as long as they can stay dry in cold weather. Take cuttings when the plant is growing (not before June) by removing a rosette and leaving it somewhere dry and cool for a week to callous over. Then place it in a very gritty compost mix and water fortnightly. It should show growth in a month or two. The remaining plant will develop new side buds that will form fresh rosettes. Q Why do my red onions always go to seed, but white onions planted at the same time in the same plot do not? A All onions, especially red ones, can respond to changes in heat or water levels by going to seed, so keep moisture and temperature steady. But the only sure way to avoid this is to plant heat-treated sets (specially prepared immature onions you can buy from garden centres) into warm soil at the end of March. Q I cut my lacecap hydrangea down to the ground last year, resulting in loads of leaves but no flowers. Help! A Lacecap hydrangeas flower on wood made the previous year, so timing is crucial. Wait until leaves are forming in early April – then remove up to a third of last year’s growth to keep the plant compact but retain flowering wood.