Vine weevils are a menace, particularly if you grow a lot of plants in pots and containers and they seem to be becoming more of a problem each year.
The adult vine weevil Otiorhynchus sulcatus , is about 1cm long , matt black, beetle-like and inclined to ‘play dead’ if disturbed while out on its evening forays. They creep about, nibbling tender leaf sections from around leaf edges, usually towards the base of your plants. Vine weevils will cause this ‘notching’ on many shrubs and herbaceous perennials and because they cannot fly they rarely attack too far up the plant. The notching is largely cosmetic damage , but right now there are also likely to be a good few young of the vine weevil around too. These creamy white grubs have a distinct gingery coloured head and are often found curled in a ‘C’ shape and nestled in amongst the plant roots, especially anything grown in a container. They’re voracious feeders, and can devastate a sizeable root system amazingly speedily. If you’ve noticed poor performance from plants in pots it is well worth looking in the compost to see if you can spot these insidious grubs! They will eat almost anything but fuchsias, begonias, polyanthus and alpines seem to be their favourites . They will seriously weaken plants and often kill them within a matter of weeks.
So what can you do? If you know that pots are definitely not infested you can prevent the vine weevil from reaching the compost to lay her eggs by standing the pot on pot-feet or blocks within a saucer kept topped up with water. The moat you create will work well because these pests can’t swim either. Each one you prevent from accessing the compost is part of the battle won, because all vine weevils are female so each one is capable of laying large numbers of eggs.
You can use a chemical drench but I personally always go for the biological control nematode treatment, it has been about for years now and, provided you follow the instructions it works really well and is totally safe for use in gardens shared with humans and other animals including pets and wildlife. If you’ve not tried it before, have a go this year, you have to send off for it (it is available here NEMATODES) as it needs to be kept cool and used fresh so that it works as it should….and then you can say goodbye to massacred root systems and tunnelled begonias, without blotting your green copy-book!