Pocket BotanistCheck these first
- Feel the soil 3 inches down to check for dryness.
- Inspect the undersides of the foliage for tiny webs.
- Check if the browning is occurring on the sunny side of the tree.
Likely causes
Drought stress
Most likelyHow to tell: The foliage feels brittle and dry to the touch, often starting at the outer edges. This happens when the tree cannot pull enough water to the ends of its branches.
What to do: Water the tree deeply once every 7 to 14 days during dry spells. Ensure the water reaches 12 inches deep into the soil to hydrate the entire root system.
Spider mites
Most likelyHow to tell: You will see tiny webbing between the needles and a dusty, yellowed appearance on the foliage. These pests thrive in hot, dry weather and suck the sap from the leaves.
What to do: Spray the foliage thoroughly with a strong stream of water to dislodge the mites. If the infestation is heavy, apply insecticidal soap or neem oil according to the label instructions.
Find out what's wrong with your arborvitae
The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.
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When to worry
It is normal for some interior foliage to brown and drop in late summer as the tree sheds older growth. Worry if the browning spreads rapidly across the outer canopy.
Stopping it coming back
Maintain a consistent watering schedule and apply a 2 to 3 inch layer of mulch around the base to retain soil moisture.
Keep your arborvitae healthy from here
Save your plant in Pocket Botanist and you get care reminders timed for this plant, plus a care history that shows what worked. Identification and a health check are free.
Questions people ask
- Should I trim off the brown tips?
- Yes, you can prune them for aesthetic reasons. Use clean, sharp shears to cut just behind the dead tissue.
- Can fertilizer fix brown tips?
- No, fertilizer can actually burn stressed roots. Focus on proper hydration first.
More problems with Arborvitae
This article was generated with AI from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.