Troubleshooting
Arborvitae problems — and how to fix them
Arborvitae (Thuja occidentalis) 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.
Winter burn / foliage bronzing
Cold, drying winds and winter sun pull moisture from the evergreen foliage faster than frozen roots can replace it, scorching it brown, especially on young or exposed plants.
Spider mites
Hot, dry conditions let spider mites build up and feed on the scales, causing stippling, bronzing and premature needle drop.
Bagworms
Bagworm caterpillars build silk-and-needle cases that hang from branches and defoliate sections of the plant if left uncontrolled.
Root rot from waterlogged soil
Heavy, poorly drained or persistently soggy soil suffocates and rots the roots, causing yellowing, dieback and decline.
Browning from drought stress
Insufficient water, particularly in newly planted specimens or containers, dries the rootball and turns interior and tip foliage brown.
Bare patches from over-pruning
Cutting back into old, leafless wood leaves permanent gaps because arborvitae does not readily regrow from bare brown stems.
Prevent arborvitae problems before they start
Most arborvitae issues are care-mismatch, not bad luck. Dial in the basics:
Arborvitae problems — FAQ
Why is my arborvitae winter burn / foliage bronzing?
Cold, drying winds and winter sun pull moisture from the evergreen foliage faster than frozen roots can replace it, scorching it brown, especially on young or exposed plants.
Why is my arborvitae spider mites?
Hot, dry conditions let spider mites build up and feed on the scales, causing stippling, bronzing and premature needle drop.
Why is my arborvitae bagworms?
Bagworm caterpillars build silk-and-needle cases that hang from branches and defoliate sections of the plant if left uncontrolled.
Why is my arborvitae root rot from waterlogged soil?
Heavy, poorly drained or persistently soggy soil suffocates and rots the roots, causing yellowing, dieback and decline.
Why is my arborvitae browning from drought stress?
Insufficient water, particularly in newly planted specimens or containers, dries the rootball and turns interior and tip foliage brown.
Why is my arborvitae bare patches from over-pruning?
Cutting back into old, leafless wood leaves permanent gaps because arborvitae does not readily regrow from bare brown stems.