Leaf Blight
Symptom category — not a single disease
36 host plants · Fungal
Last updated
Water-soaked lesions expand into brown spots with distinctly darker margins, causing significant premature defoliation that weakens the plant substantially. Remove affected foliage immediately when symptoms appear, improve soil drainage around roots, and space plants for air movement. Rake fallen leaves regularly throughout the season. Avoid overhead watering which keeps foliage wet and spreads fungal spores.
Propagate from disease-free stock plants. Use seed from British Columbia coastal, low-elevation populations.
Quick Reference
Agent Type
fungal
Causal Agent
Symptom category — not a single disease
Host Plants
36
Management
Cultural Controls
- Good sanitation: clean up and dispose of fallen blighted leaves around valuable landscape trees.
- Good air circulation is important since fungal diseases are more severe in crowded, humid conditions.
- Avoid stressing plants with poor planting location or improper culture.
- For madrone: prefer native soils with excellent drainage, full or partial sun; do not irrigate established trees.
Host Plants (36)
Arbutus menziesii Pacific Madrone Arbutus unedo Strawberry Tree, Killarney Strawberry Tree, Madroño Athrotaxis laxifolia Tasmanian Pencil Pine, Summit Cedar Callitropsis nootkatensis Alaska Cedar, Nootka Cypress, Nootka Falsecypress, Yellow Cedar Calocedrus decurrens Incense Cedar Cryptomeria japonica Japanese Cedar Juniperus californica California Juniper, California White Cedar, Desert White Cedar Juniperus cedrus Canary Island Juniper Juniperus chinensis Chinese Juniper Juniperus communis Common Juniper Juniperus conferta Juniperus conferta Juniperus deppeana Alligator Juniper, Checkered-bark Juniper Juniperus formosana Formosan Juniper Juniperus grey Juniperus grey Juniperus horizontalis Creeping Juniper Juniperus monosperma Oneseed Juniper Juniperus occidentalis Western Juniper Juniperus osteosperma Utah Juniper Juniperus pingii Ping Juniper Juniperus procumbens Japanese Garden Juniper, Bonin Island Juniper, Ibuki Juniper Juniperus rigida Temple Juniper, Needle Juniper Juniperus rigida subsp. conferta Shore Juniper Juniperus sabina Savin Juniper Juniperus scopulorum Rocky Mountain Juniper Juniperus squamata Singleseed Juniper, Flaky Juniper, gao shan bai Juniperus virginiana Eastern Redcedar Pencil Cedar Microbiota decussata Russian Arborvitae, Siberian Cypress Morella californica Pacific Waxmyrtle California Waxmyrtle California Bayberry Morella pensylvanica Northern Bayberry Candleberry Morella rubra Red Bayberry Chinese Bayberry Japanese Bayberry Platycladus orientalis Chinese Arborvitae, Oriental Arborvitae Taiwania cryptomerioides Formosan Redwood Taiwan Cedar Taiwania, Coffin Tree Tamarix parviflora Small-flowered Tamarix, Salt Cedar Thujopsis dolabrata Elkhorn Cedar, Deerhorn Cedar, Hiba Arborvitae, False Arborvitae Widdringtonia nodiflora Berg Cypress Mountain Cypress, Mountain Cedar Widdringtonia schwarzii Willowmore Cedar
Sources & References
Data Maturity Baseline Extension data. Expert review underway.