READERS’ LETTERS

CATCHING ADULT

VINE WEEVILS

Every year is the same, she says. Cheryl Parker sent me photographs of the leaves of several of her evergreen shrubs that are completely (there is no better word for it) mauled. She never sees any traces of the culprits. Are they visiting at night and vanishing without trace?

Yes, they are – almost. This is the work of vine weevils, black snouty, leggy, slowmoving beetles about 1cm long that hide among leaf litter during the day, grazing on lower leaves of favoured evergreens (euonymus, rhododendrons, to name two) overnight. They at their most active now, and if Cheryl is quick off the mark one balmy evening, spreading newspaper on the ground under her tattered shrubs, returning at dead of night with a torch to shake the foliage, she may hear them drop on to the paper, which she can then dispose of.

This will nobble those beetles that would otherwise lumber off to lay eggs in the soft compost around, especially, primulas, heucheras and violas, doubly especially in containers.

While the adults disfigure shrubs, which is bad enough, they rarely kill them. It is their soil-dwelling grubs, white, curved and c-shaped, that gardeners most often see and dread, mostly in container compost, where they destroy “host” plants. There are two ways of getting rid of them (one biological, one chemical, for containers only), both called Vine Weevil Killer, both soil-drenches. I suggest that Cheryl does her best to identify where the grubs might be in her garden and uses one or other in autumn and spring.

HOW TO GROW A

POTTED OLIVE TREE Q We are delighted to have been given a small olive tree as a gardenwarming present for our London home. It is a slightly unevenly shaggy lollipop about 120cm high, with a trunk tied tightly to a cane in a plastic pot of rock-hard soil 20cm high and wide. How should we proceed?

– Hannah Fox – via email A Repot your little tree into a heavy container (terracotta, wood, or even ceramic) which is a little larger. This will give the plant greater stability and room for its roots to develop. Olive trees grow slowly and belong in stony soil with good drainage, so don’t use a “multipurpose” compost, go for something loam-based such as John Innes No3, and even add a little grit to it.

Leave the stake in place for a few months, but make sure the ties are not too tight. Give your tree as much sun as you can during the summer. Olive trees are hardy in London but may need to be moved close to the shelter of your house during a cold and windy winter, to prevent leaf loss. Normally, olives are pruned in spring, unruly shoots shortened, and inwardsgrowing shoots cut out.

You could give the plant a gentle tidy-up now (looking for and tweaking out any inward-growing shoots). You won’t need to feed it this year but water regularly. It may reward you with flowers and even olives next year.