Troubleshooting
Filbert 'Ennis' problems — and how to fix them
Filbert 'Ennis' (Corylus maxima 'Ennis') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Poor pollination / blank nuts
'Ennis' is self-sterile; without a compatible pollenizer (e.g. another filbert flowering at the same time) catkins shed pollen but few nuts set. Plant two or more cultivars.
Grey squirrels
Squirrels strip nuts while still green, often before harvest. Net low bushes or harvest promptly as husks begin to brown.
Eastern filbert blight
Caused by the fungus Anisogramma anomala, this canker disease can kill European filberts. 'Ennis' is susceptible; remove and burn cankered wood and avoid the disease where prevalent.
Nut weevil
Hazelnut weevil larvae bore into developing kernels, leaving exit holes. Clear fallen infested nuts and cultivate beneath the tree to disrupt overwintering grubs.
Prevent filbert 'ennis' problems before they start
Most filbert 'ennis' issues are care-mismatch, not bad luck. Dial in the basics:
Looking for filbert 'ennis' in general rather than its problems? Read the full filbert 'ennis' care guide — light, water, soil and feeding.
Filbert 'Ennis' problems — FAQ
Why is my filbert 'ennis' poor pollination / blank nuts?
'Ennis' is self-sterile; without a compatible pollenizer (e.g. another filbert flowering at the same time) catkins shed pollen but few nuts set. Plant two or more cultivars.
Why is my filbert 'ennis' grey squirrels?
Squirrels strip nuts while still green, often before harvest. Net low bushes or harvest promptly as husks begin to brown.
Why is my filbert 'ennis' eastern filbert blight?
Caused by the fungus Anisogramma anomala, this canker disease can kill European filberts. 'Ennis' is susceptible; remove and burn cankered wood and avoid the disease where prevalent.
Why is my filbert 'ennis' nut weevil?
Hazelnut weevil larvae bore into developing kernels, leaving exit holes. Clear fallen infested nuts and cultivate beneath the tree to disrupt overwintering grubs.