ASK MONTY

QI have an east-facing arbour with a clematis that seldom produces flowers. We prune it in February. What can I do?

AIt sounds like you’re pruning a group two clematis as if it were a group three. There are three groups of clematis. Group two has large flowers in late spring and early summer produced on old shoots and then a second batch on new shoots in late summer. Prune it back by a third after its first flush of flowers.

QMy container-grown, ten-year-old wisteria has always flowered prolifically, but not this year. What has happened?

AIt might need repotting, as wisteria are greedy and, after ten years, the roots will still be growing. Repot into a large container and give it a weekly liquid seaweed feed.

QEvery year I battle with horrible lily beetles. Please could you tell me how I can get rid of them for good?

AI’m afraid you’ll never be completely rid of the bright red lily beetle. The only way to deal with them is to pick them off and kill them whenever you see them. Creep up on them (the beetles can feel the vibration of your movements) and remove them while they’re still on the leaves.