About this product
Full description
There's a specific moment every serious gardener eventually experiences. A previously-thriving plant — often a heuchera, a primula, a strawberry, or a container fuchsia — visibly wilts over the course of a week, despite regular watering. You lift the pot or dig it up, and the root system is gone. Under the soil, you find them: fat cream-white C-shaped grubs with brown heads, munching contentedly through what used to be your plant. This is the vine weevil moment, and it's the reason nematode treatment exists. Vine weevil (Otiorhynchus sulcatus) is the single most destructive pest of container-grown ornamental plants in the UK, and the nematode is the biological answer that actually works.
Made by our biological control partners at Ladybird Plant Care. Live product, dispatched from their refrigerated facility at peak viability, direct to your door.
How the nematodes work
These are microscopic parasitic worms — invisible to the naked eye — that live naturally in UK soils in low numbers. The species used for vine weevil control is Steinernema kraussei, a cool-temperature specialist that stays active down to 5°C, making it ideal for the autumn and early spring windows when vine weevil grubs are actively feeding underground. Once watered into the soil, the nematodes actively search out vine weevil grubs, enter through natural body openings, and release symbiotic bacteria that kill the grub within 24 to 48 hours. The nematodes then feed on the grub, multiply inside it, and emerge as a new generation ready to find the next host. Each treatment can knock down an established grub population in a few weeks and offer residual protection for months.
Zero risk to humans, pets, plants, birds, bees, pollinators, or beneficial insects. Nematodes only parasitise their specific target grub — other soil life is untouched. Once the vine weevil population has collapsed, the nematodes die back naturally.
Identifying vine weevil damage
Vine weevil have two life stages that damage plants differently, so effective treatment depends on knowing what you're looking at:
- Adult damage (leaves) — the distinctive notched, C-shaped bite marks along leaf edges. Look particularly at heucheras, rhododendrons, camellias, primulas, viburnums. Damage appears from spring onwards. Adults are all female, flightless, nocturnal beetles about 1cm long, matt black with tiny yellow flecks. During the day they hide in leaf litter, so you rarely see them. Adult damage is unsightly but rarely fatal
- Grub damage (roots) — this is what kills plants. Sudden wilting despite adequate water, or a plant that pulls out of the pot with almost no root system attached. Digging into the soil reveals the C-shaped cream-white grubs (up to 1cm long) with distinctive brown heads. Grubs feed on roots July through March, with peak damage October to March
- Not vine weevil — other grubs in soil include chafer grubs (bigger, up to 3cm, live in lawns) and various beetle larvae. Vine weevil grubs are specifically C-shaped, cream-white bodies with brown heads, and typically under 1cm long
When to apply
The autumn window is by far the most important. Vine weevil grubs feed most actively October through November before winter dormancy, and treating during this window catches the largest number of grubs when they're most vulnerable:
- Autumn (September to November) — the main treatment window. Soil is still warm from summer but starting to receive rain, giving the moist warm conditions nematodes need. Grubs are actively feeding and easy for nematodes to find
- Spring (March to May) — secondary window for treating over-wintered grubs before they pupate. Also useful for treating any adult egg-laying that started in April
- Not recommended winter — soil below 5°C means nematodes are inactive. Wait for soil temperature to lift
- Not recommended high summer — hot dry soil kills nematodes before they can find grubs. Wait for cooler autumn conditions
For serious ongoing vine weevil problems, treat every autumn as a matter of routine. Prevention is considerably easier than dealing with plant collapse.
Choosing your pack size
Two pack sizes cover most garden and container situations:
- 12 sqm — treats approximately 12 square metres of soil. Suitable for container-heavy gardens: patio pot collections, greenhouse benches, cold frames, small border areas. The starting size for most home gardens where vine weevil is affecting specific plants
- 100 sqm — treats approximately 100 square metres. Suitable for larger gardens where vine weevil has spread through mixed borders, allotments, nursery-scale container growing, or gardens where you're treating the whole area preventatively
Cost-per-square-metre is significantly better on the 100 sqm pack, so if you have any doubt about coverage, the larger pack usually pays for itself.
Setting them up
Nematode application is easier than most biological controls, but a few practical points matter:
- Water soil thoroughly beforehand — nematodes need moisture to move through soil. Dry soil kills them within hours of application
- Mix nematodes with cool water in a watering can (fine rose) or through a hose feeder. Follow the pack instructions for dilution rates
- Apply in cool conditions — late afternoon or early evening is ideal. Avoid direct sunlight during application, which can damage nematodes
- Water in gently after application to move the nematodes down into the top layer of soil where the grubs are
- Keep soil moist for two weeks after application — water regularly, particularly if autumn is dry
- Apply to soil, not leaves — nematodes are soil-dwelling. Spraying onto leaves is ineffective and wasteful
- Container plants first if you have limited product — containers are most vulnerable to vine weevil and easiest to treat effectively
What not to combine with
Nematodes are living organisms and can be killed by conditions or chemicals that suit vine weevil grubs perfectly well:
- Dry soil — the single most common cause of nematode treatment failure. Water thoroughly before and after application
- Cold soil (below 5°C) — nematodes are dormant, treatment is wasted. Wait for warmer conditions
- Hot dry soil (above 30°C) — conditions kill nematodes before they reach the grubs. Wait for autumn or evening application
- Systemic insecticides in the soil — anything you've applied recently as a soil drench or granule that's still active. Wait 4-6 weeks after chemical treatment before applying nematodes
- Bright direct sunlight during application — UV kills nematodes on contact. Apply in dull weather or late afternoon
About Ladybird Plant Care
Ladybird Plant Care are our biological pest control partners, specialising in live predator, parasite and nematode products dispatched at peak freshness from their refrigerated facility direct to your door. They handle the cold chain, timing and dispatch schedule for all Bishy biological control products including these Vine Weevil Nematodes, our Encarsia whitefly parasites, Aphid Midge, Lacewing Larvae, Ladybirds for Aphids, and the full biological range. The Bishy Barnabee — our namesake ladybird — sits at the heart of why we work with Ladybird Plant Care: chemical-free, biology-first gardening is genuinely aligned with what we do.
A note on ordering timing
Biological controls are ordered fresh rather than held in stock. This means there is a delay of a few days between placing your order and dispatch. Order by 10am Monday for same-week despatch. Orders placed later in the week ship the following week. This is standard for live biological controls across all UK suppliers; freshness matters more than speed for these products. Apply nematodes within 2-3 days of arrival for best results.
Specifications
- Species: Steinernema kraussei (parasitic nematode, cool-temperature specialist)
- Target pest: Vine weevil grubs (Otiorhynchus sulcatus)
- Format: powder-carrier mix, added to water for application
- Pack sizes: 12 sqm coverage or 100 sqm coverage
- Application: watered into soil with can or hose feeder
- Soil temperature range: active above 5°C, ineffective above 30°C
- Season of use: primary autumn (September-November); secondary spring (March-May)
- Safety: harmless to humans, pets, plants, pollinators, and beneficial insects
- Dispatch: direct from Ladybird Plant Care, order by 10am Monday for same-week despatch
- Post-arrival: apply within 2-3 days; store cool (5-10°C) in refrigerator if delay unavoidable
A note on prevention: vine weevil often arrives on new plants bought from nurseries or garden centres. If you're bringing new container-grown plants home, an autumn nematode treatment of the pot before adding it to your collection catches any imported grubs before they spread. It's considerably easier than dealing with an established infestation across the garden. Similarly, if a plant collapses suddenly and grubs are found, treat every container within a few metres — vine weevil adults can walk between pots at night and will have laid eggs across a wider area than the initial casualty suggests.
What's included
Application instructions
Care and use
- Apply within 2-3 days of arrival for best results
- If delay unavoidable, store cool (5-10°C) in refrigerator, upright,
unopened