Root weevils attacking rhododendrons

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Q: What can I do to control root weevils in my rhododendrons? Are there options other than nemetodes?

Root weevils are challenging to control since they feed on a wide variety of plant materials besides rhododendrons. Damage can range from severe (broadleaf, like on rhododendrons) to very subtle (hardly noticeable on a cedar hedge). The insect can also migrate over time.

Rhododendron cultivars tend to vary in their susceptibility. I have also observed that newly planted rhododendrons and/or plants under cultural/environmental stress can be particularly vulnerable to weevil attack.

Handpicking is the preferred way to get rid of them. You could also try a sticky band on the stem to deter migration. Nematodes are a good tool to incorporate for ongoing management of this pest.

I believe it’s also important to review your cultural techniques. For example, has there been enough mulching and watering to keep plants growing in a stress-free environment?

As a last resort, “shovel prune” – remove the plant(s) in question.