The Vine Weevil is a garden plant pest problem that can be difficult to control. Gardeners with vine weevil will need to take measures to control them.

Vine weevil is one plant insect pest that most gardeners live in fear of. And it is a pest to worry about. Suddenly, otherwise healthy-looking plants collapse and die thanks to the root-eating, soil-borne grubs.

You should suspect a vine weevil attack if watering does not revive the plant. In severe cases, plants may be completely severed from their roots at ground level.

In the past, their favourite food was fuchsias, cyclamen, begonias and primulas. But in recent years they have become less fussy and will make a meal of a much wider range of plants - especially any that are growing in containers. This is possibly due to the use of peat-based and peat-free composts - being less gritty than John Innes composts, the adults are more likely to use them for laying eggs.

What to do if you notice a Vine Weevil attack?

Don't despair, there are several ways of dealing with this plant-nibbling nasty. It is important to be vigilant and keep a close eye on all your plants - especially those that are known to be favourites on the menu.

Always check the root balls for grubs before you buy plants. Check when potting up or repotting plants, and destroy any that you see; it usually pays to dispose of affected compost too.

Because vine weevil is such a destructive pest, every effort must be taken to control both the adults and the soil-borne grubs.

There are three ways of controlling vine weevil: chemical, biological control and physical barriers.

Typical vine weevil grubs will eat the roots of a wide range of different plants.

They are creamy-white, up to 13mm (0.5in) long, C-shaped, with a brown head and no legs.

Often the first signs of damage are only spotted when a plant completely wilts and dies.

Commercial nurseries sometimes add a strong chemical called Suscon Green to the compost, which gives good control. It is worth asking when you are buying particularly susceptible plants if Suscon Green has been used.

There are a number of insecticides that can be used to treat plants and give protection against attack. Bayer Provado Vine Weevil Killer 2 and Scotts Miracle-Gro BugClear Ultra Vine Weevil Killer can be used for any container-grown plants (apart from edible ones); they are watered onto the compost.

BugClear Ultra for Pots and Westland Bug Attack Quick Sticks are insecticide pins that are inserted into the compost.

Provado Ultimate Bug Killer is sprayed onto plant foliage to kill leaf pests, but may also give some control of vine weevil grubs (some edible plants can be treated; check the label first). Scotts BugClear Ultra and Westland Plant Rescue Bug Killer for Ornamental Plants are similar but can only be used on ornamentals.

If you don't like using pesticides, use a biological control based on nematodes. These microscopic creatures enter the bodies of the grubs and release a specific bacteria that poisons and kills them. They then multiply and go on to attack other grubs.

An alternative to Nematodes, and synthetic chemicals, is the use of a natural soap based product like Armillatox.

Controlling Vine Weevil beetles

One of the most effective - but time-consuming methods of controlling the adult vine weevil beetles is to check your plants at night when they are active and feeding. They can then be scooped up and disposed of.

Another way is to use a physical barrier as the adult beetles cannot fly from plant to plant. Stand potted plants on upturned pots sat in saucers of water - the adults can't swim. Or surround the pots with Barrier Glue available from Agralan - the adults cannot walk across it.

With either of these methods it is important to move plants away from walls or greenhouse/conservatory walls as the adults can jump down onto them; they cannot fly. Physical barriers on top of the soil or compost also work very well. Add a 2cm (0.75in) deep layer of sharp grit or gravel on top of the compost or around the base of the plant to prevent the adults from laying eggs; the egg-laying structure is irritated by the scratchy feel.

Vine Weevil eggs

If you spot golden-brown or clear egg-like objects in the soil or compost then they're NOT vine weevil eggs. The eggs are tiny and you'd need a hand lens to even see them. Clear spheres are usually slug or snail eggs and the golden-brown ones are actually controlled-release fertiliser!