Troubleshooting
Shagbark manzanita problems — and how to fix them
Shagbark manzanita (Arctostaphylos tomentosa) 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.
Root rot (Phytophthora)
The most common and fatal problem. Caused by summer irrigation or heavy clay soils. Leaves yellow, then brown, and the plant rapidly collapses. Ensure excellent drainage and stop all summer watering once established.
Leaf gall (Exobasidium)
A fungal pathogen that causes pale, waxy, distorted leaf galls in spring. Remove and destroy affected tissue. Improves airflow by pruning out crowded interior branches. Generally not fatal.
Poor flowering / leggy growth
Usually caused by insufficient sun or overly rich soil. Ensure full sun exposure and avoid fertilizing or heavily amending planting soil. Thin lightly after flowering to maintain shape.
Prevent shagbark manzanita problems before they start
Most shagbark manzanita issues are care-mismatch, not bad luck. Dial in the basics:
Shagbark manzanita problems — FAQ
Why is my shagbark manzanita root rot (phytophthora)?
The most common and fatal problem. Caused by summer irrigation or heavy clay soils. Leaves yellow, then brown, and the plant rapidly collapses. Ensure excellent drainage and stop all summer watering once established.
Why is my shagbark manzanita leaf gall (exobasidium)?
A fungal pathogen that causes pale, waxy, distorted leaf galls in spring. Remove and destroy affected tissue. Improves airflow by pruning out crowded interior branches. Generally not fatal.
Why is my shagbark manzanita poor flowering / leggy growth?
Usually caused by insufficient sun or overly rich soil. Ensure full sun exposure and avoid fertilizing or heavily amending planting soil. Thin lightly after flowering to maintain shape.