Sycamore Maintenance
Sycamores and London Planetrees are widely planted in Colorado for their massive size, mottled bark, and excellent shade. While generally tough, they are prone to anthracnose, powdery mildew, borers, cankers, and drought-related stress.
- Species
- Sycamore
- Botanical Name
- Platanus occidentalis – American Sycamore; Platanus × acerifolia – London Planetree
- Group
- Deciduous Trees
- Tracked Problems
- 7
Seasonal Calendar
| Problem | Type | Active Season |
|---|---|---|
| Anthracnose | Fungus | Spring infection; symptoms Spring–Early Summer |
| Powdery mildew | Fungus | Summer–Fall |
| Sycamore lace bug | Insect | Summer |
| Scale insects | Insect/scale | Spring crawlers; visible year-round |
| Borer insects | Insect/borer | Summer |
| Canker diseases | Fungus | Spring–Fall |
| Leaf scorch | Abiotic | Summer–Fall |
Pest & Disease Guide
Anthracnose
Common symptoms
- Browning and curling leaves
- Twig dieback in spring
- Early defoliation
Treatment & management
- Remove fallen leaves
- Improve airflow
- Professional fungicide if severe
Powdery Mildew
Common symptoms
- White powdery coating
- Reduced vigor
Treatment & management
- Improve airflow
- Avoid overhead watering
- Treat only if severe
Lace Bugs
Common symptoms
- Yellow stippling on leaves
- Leaf browning
Treatment & management
- Rinse foliage
- Encourage predators
- Treat if heavy infestation
Scale Insects
Common symptoms
- Honeydew and sooty mold
- Bumps on bark
- Branch dieback
Treatment & management
- Treat crawler stage
- Horticultural oil
- Prune infested areas
Borers
Common symptoms
- Exit holes
- Sawdust/frass
- Branch dieback
Treatment & management
- Deep watering
- Avoid bark injury
- Preventive treatments if needed
Canker Diseases
Common symptoms
- Sunken bark areas
- Oozing sap
- Branch dieback
Treatment & management
- Prune infected limbs
- Sanitize tools
- No chemical cure
Leaf Scorch
Common symptoms
- Brown leaf edges
- Early leaf drop
- Burned appearance
Treatment & management
- Deep watering
- Mulch base
- Reduce heat exposure
When to Worry
- Repeated severe anthracnose defoliation
- Large cankers on major limbs
- Borer damage with canopy thinning
- Heavy scale infestation
- Rapid upper canopy dieback
- Major limb failure risk
Mostly Cosmetic
- Light anthracnose
- Powdery mildew patches
- Minor lace bug activity
- Some drought scorch
- Early leaf drop in extreme heat
Notes
These issues often require professional arborist evaluation due to tree size and risk.
These typically improve with proper watering and seasonal recovery.
Related Resources
Related Services
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The Root exists to help you understand your landscape. When a tree needs hands-on evaluation, a Great Western arborist can look at it in person.