Bleeding Canker

Phytophthora spp. (P

45 host plants

Last updated

Data Maturity Structured

This profile synthesizes data from multiple published sources. Expert field review is in progress.

Bleeding canker is caused by Phytophthora species that invade bark and outer sapwood from infected soil. You'll see dark sap continuously oozing from large cankers on maples and other susceptible deciduous trees. The disease is particularly problematic in wet environments and irrigated landscapes where tree trunks are regularly wetted. Watch for sunken lesions with reddish-brown staining. Keep sprinkler irrigation off tree trunks and improve drainage.

Do not let sprinkler irrigation wet landscape tree trunks. Avoid ponding of water around trees. Prune affected branches well below visible symptoms and sterilize tools between cuts. Avoid pruning during wet weather, which spreads the pathogen through fresh wounds. Maintain plant vigor through proper watering and site management.

Quick Reference

Causal Agent
Phytophthora spp. (P
Host Plants
45
Favorable Conditions
Wet, poorly drained soils; trunk wetting from sprinkler irrigation; recent tr...

Management

Vulnerability Window

Symptoms develop and progress during wet, warm periods, typically spring through early summer in the Puget Sound region (May-July). Trees under chronic trunk wetting from irrigation remain vulnerable year-round. Winter is less active but oomycete survives in bark. # Source: PNW Plant Disease Management Handbook - Bleeding Canker

What Triggers Infection

Wet, poorly drained soils; trunk wetting from sprinkler irrigation; recent trunk wounding; clay-heavy soils; waterlogged nursery conditions; warm temperatures

Cultural Controls

  • Do not let sprinkler irrigation wet landscape tree trunks.
  • Avoid ponding of water around trees.
  • Avoid over- or underwatering plants.
  • Plant in well drained areas.
  • Prevent mechanical injury to trees.

Host Plants (45)

Acer buergerianum Trident Maple, Three-toothed Maple Acer campestre Hedge Maple, Field Maple, Common Maple Acer capillipes Red Stripebark Maple, Red Snakebark Maple, Hakkoda Maple Acer carpinifolium Hornbeam Maple Acer circinatum Vine, Maple Acer coriaceifolium Leatherleaf Maple Acer crataegifolium Hawthorn, Maple Acer davidii David Maple, Père David's Maple Acer freemanii Freeman Maple, Hybrid Red Maple Acer ginnala Acer ginnala Acer glabrum Rocky Mountain Maple, Rock Maple, Douglas Maple, Dwarf Maple Acer glabrum var. douglasii Douglas Maple, Dwarf Maple, Rocky Mountain Maple Acer grandidentatum Bigtooth Maple, Western Mountain Sugar Maple, Rocky Mountain Sugar Maple Acer griseum Paperbark Maple Acer henryi Henry's Maple Acer japonicum Fullmoon Maple Acer macrophyllum Bigleaf Maple Acer maximowiczianum Nikko Maple Acer miyabei Miyabe Maple Acer monspessulanum Montpellier Maple Acer negundo Boxelder Manitoba Maple, Ash-leaved Maple Acer nipponicum Nippon Maple Acer oblongum Evergreen Maple, Smooth Leaf Maple Acer oliverianum Oliver Maple Acer opalus subsp. obtusatum Bosnian Maple Acer palmatum Japanese Maple Acer palmatum var. dissectum Dissected Japanese Maple Acer pensylvanicum Striped Maple, Moosewood Maple Acer pentaphyllum Acer pentaphyllum (no common name) Acer pictum Painted Maple Acer platanoides Norway Maple Acer pseudoplatanus Planetree Maple, Sycamore, Maple Acer rubrum Red Maple Acer rufinerve Redvein Maple, Honshu Maple Acer saccharinum Silver Maple Acer saccharum Sugar Maple Acer sempervirens Cretan Maple Acer shirasawanum Shirasawa Maple Acer spicatum Mountain Maple, Moose Maple Acer tataricum Tatarian Maple, Tartarian Maple Acer tataricum subsp. ginnala Amur Maple Acer tegmentosum Manchurian Stripebark Maple, Manchustriped Maple Acer triflorum Three Flowered Maple Acer truncatum Purpleblow Maple, Shantung Maple Acer velutinum Velvet Maple