Willow
(Salix spp. — includes Weeping Willow, Golden Willow, Globe Willow, and others)
Willows grow quickly and prefer moist soils, making them common in irrigated landscapes. They are attractive but prone to pests, disease, and structural issues, especially in dry or windy sites.
Seasonal Pest & Disease Calendar
| Problem | Type | Active Season |
|---|---|---|
| Willow leaf beetle | Insect | Spring–Summer |
| Aphids | Insect | Spring–Fall |
| Scale insects | Insect | Spring crawlers; visible year-round |
| Borers | Insect/borer | Summer |
| Canker diseases | Fungus | Spring–Fall |
| Leaf spot / rust | Fungus | Spring–Summer |
| Environmental stress | Abiotic | Summer–Fall |
Pest & Disease Guide (Homeowner-Friendly)
Willow Leaf Beetle
Common symptoms- Skeletonized leaves
- Patchy defoliation
- Usually cosmetic
- Rinse foliage
- Treat severe cases
Aphids
Common symptoms- Sticky honeydew
- Sooty mold
- Leaf curling
- Water spray
- Encourage beneficial insects
Scale Insects
Common symptoms- Bumps on twigs
- Yellowing leaves
- Treat crawler stage
- Horticultural oil
Borers
Common symptoms- Exit holes
- Frass buildup
- Branch dieback
- Reduce stress
- Deep watering
- Professional treatment if needed
Canker Diseases
Common symptoms- Sunken or cracked bark
- Oozing sap
- Dieback
- Prune infected limbs
- Improve tree vigor
Leaf Spot / Rust
Common symptoms- Leaf spotting
- Premature leaf drop
- Remove leaves
- Improve airflow
Environmental Stress
Common symptoms- Leaf scorch
- Broken limbs
- Sparse canopy
- Deep watering
- Structural pruning
- Avoid exposed sites
When to Worry vs. When It’s Cosmetic
When to Worry (action recommended)
- Large branch breakage
- Heavy borer activity
- Expanding cankers
- Severe scale infestation
- Repeated defoliation
Willows grow fast but have weak wood, making structural issues a major concern.
Mostly Cosmetic (monitor only)
- Light beetle feeding
- Mild aphid activity
- Minor leaf spotting
- Occasional tip dieback
These typically resolve with watering and seasonal recovery.