Vine weevil
Beetles notch leaf edges at night while their white grubs eat roots, killing potted plants from autumn to spring.
What you'll see
- Irregular notches chewed into leaf edges, especially on rhododendrons, azaleas and container plants.
- Potted plants wilt and collapse from autumn to spring even though the mix is moist.
- Plump, C-shaped, white legless grubs with brown heads, up to 3/8 inch (10 mm) long, among the roots.
Why it happens
Flightless adult beetles, nearly all female, lay hundreds of eggs in soil and pots in summer. The grubs feed on roots and stem bases through autumn and winter.
How to fix it
- Unpot wilting plants, pick the grubs out of the roots and repot in fresh mix.
- Pick adults off plants and walls by flashlight on mild evenings.
- Water in insect-killing nematodes sold for vine weevil in late summer, when the mix is above about 41°F (5°C), as the label says.
Keep it from coming back
- Check the roots of new plants before planting or potting them.
- Trap adults with sticky barriers around pots or on greenhouse benches.
- Look under pots and benches by day, where adults hide.
Sources
General guidance, not a diagnosis. For valuable, edible or outdoor crops, check with a local extension service or plant expert. Use any product exactly as its label says, and keep children and pets away while it dries.