Tackle vine weevils now, before they take a hold, as early action can make all the difference. Swing into action while the damage is limited to just a few notches in the leaves – the first tell-tale signs that these nasty little bugs are about – and you’ll head off potential disaster: vine weevil grubs can kill a plant outright once they get going.
Vine weevils affect all kinds of plants, but some are particularly susceptible. Weevils are often found among the roots of container-grown plants; they are also partial to heucheras and strawberries.
Usually the first signs you’ll notice are irregular notches munched out of the margins of each leaf. This is a sure sign adult vine weevils are around. By itself, this initial damage isn’t too serious, but it’s an early warning sign. Adults mean eggs, laid in the compost by the plant’s roots – and that’s where the real damage occurs.
Those eggs hatch out into small (1cm long) C-shaped white grubs, each with a chestnut head. These start feasting on your plants’ roots from August onwards. If you let them grow unchecked, by early autumn they can eat out the entire root system: often the first you’ll know of the damage taking place underground is when your plant keels over, its roots completely eaten away.
At the garden centre here in Cornamagh we’re ready and waiting to fight back. Vine weevil treatments tackle the bugs while they’re still tiny, and before they do serious damage. Choose between a chemical treatment, or nematodes – natural predators which eat the grubs the moment they hatch. Both are applied in the same way: just water them onto the compost in pots, or in the ground around vulnerable plants, as soon as you spot those telltale notches. One treatment should protect the plant for the rest of the season.