Troubleshooting
Columnar Italian Cypress problems — and how to fix them
Columnar Italian Cypress (Cupressus sempervirens 'Stricta') 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.
Seiridium canker
The most serious disease; causes branch dieback and streaks of resin. Remove affected branches promptly and avoid bark wounds.
Aphids
Aphids can cluster on new growth. A strong water jet or insecticidal soap resolves most infestations.
Root rot in wet soils
Overwatering or poor drainage causes rapid decline. Ensure excellent drainage before planting.
Snow and ice damage
Heavy snow loads can splay the tight column permanently. Gently knock snow off after snowfall.
Bagworm
Bagworms can defoliate branches in summer. Hand-remove bags or treat with Bt caterpillar control.
Prevent columnar italian cypress problems before they start
Most columnar italian cypress issues are care-mismatch, not bad luck. Dial in the basics:
Columnar Italian Cypress problems — FAQ
Why is my columnar italian cypress seiridium canker?
The most serious disease; causes branch dieback and streaks of resin. Remove affected branches promptly and avoid bark wounds.
Why is my columnar italian cypress aphids?
Aphids can cluster on new growth. A strong water jet or insecticidal soap resolves most infestations.
Why is my columnar italian cypress root rot in wet soils?
Overwatering or poor drainage causes rapid decline. Ensure excellent drainage before planting.
Why is my columnar italian cypress snow and ice damage?
Heavy snow loads can splay the tight column permanently. Gently knock snow off after snowfall.
Why is my columnar italian cypress bagworm?
Bagworms can defoliate branches in summer. Hand-remove bags or treat with Bt caterpillar control.