Root Rot (Armillaria ostoyae)
Armillaria ostoyae
42 host plants
Last updated
Data Coverage 3 of 6 dimensions
This Armillaria root rot species causes decay in forest soils, affecting conifers and other woody plants. Remove severely infected trees. Improve drainage where possible. Monitor stands for disease symptoms. Early removal of infected trees helps contain spread. Proper drainage and good site selection are critical to prevent root disease problems. Monitor plants for early signs of decline or wilting Early detection and prompt management of symptoms help limit disease spread.
Root rots thrive in waterlogged soil, so drainage is your most important intervention. Avoid overwatering and ensure the planting site drains well. Remove severely affected plants to prevent spread to neighbors through root contact or contaminated soil. When replanting, choose resistant species or improve soil structure before putting anything back in the ground.
Quick Reference
Causal Agent
Armillaria ostoyae
Host Plants
42
Management
Cultural Controls
- Integrate several cultural and/or chemical tactics to manage this disease. Plant only disease-free plants. Inspect and discard any incoming diseased nursery stock. Amend soils with composted sawdust or bark mulch to provide good aeration for roots. Plant in beds raised so that the top of the bed is at least 12 inches above the surrounding soil. Ame
- Plant healthy seedlings in soil known to be free of the organism. Do not plant in soil with poor drainage or in areas that receive drainage from roads. Prevent wounding at the base of trees or to roots from nearby construction or harvesting operations. Avoid extensive gardening (mulching and planting susceptible flowering plants) under cedar hedges
- Preventive measures are paramount. Plant no deeper than the tree grew in the nursery. Dogwoods have shallow root systems, and planting too deeply can mean the tree will fail to thrive. Dogwoods are understory trees, so plant where they will have at least partial shade. Provide supplemental water during the summer; water with a soaker hose 6 inches
- Do not overwater plants. Blue cultivars should be grown at a pH of 4.5 to 5.0 and pink cultivars at 5.5 to 6.0. Aluminum sulfate is needed for the blue color development but additions to the soil may tie up needed phosphorus. Provide good drainage for plants in beds, fields, or containers. Place containers on gravel beds (4 inches or more deep) to
- Do not overwater plants. Provide good drainage for plants in beds, fields, or containers. Place containers on gravel beds (4 inches or more deep) to allow drainage. Do not place containers on poly sheets; they can prevent containers from draining into soil and allow contaminated drainage water to spread from the base of one container to another. Av
Host Plants (42)
Pinus albicaulis Whitebark Pine, Scrub Pine, White Pine Pinus aristata Bristlecone Pine, Rocky Mountain Bristlecone Interior Bristlecone Pinus attenuata Knobcone Pine Pinus banksiana Jack Pine, Scrub Pine, Banksian Pine, Hudson Bay Pine Pinus bungeana Lacebark Pine, Whitebark Pine, Baipi Song Pinus canariensis Canary Island Pine Pinus cembra Swiss Stone Pine Pinus contorta Lodgepole Pine Pinus contorta var. contorta Shore Pine Pinus contorta var. latifolia Rocky Mountain Lodgepole Pine Pinus coulteri Coulter Pine, Bigcone Pine Pinus densiflora Japanese Red Pine Pinus edulis Pinyon Pine, Piñón Pine, Two-needle Pinyon Colorado Pinyon Pinus elliottii Slash Pine, Swamp Pine Pinus flexilis Limber Pine, Rocky Mountain White Pine Pinus halepensis Aleppo Pine, Jerusalem Pine Pinus heldreichii Bosnian Pine, Snakeskin Pine Pinus jeffreyi Jeffrey Pine, Western Yellow Pine, Bull Pine Pinus kwangtungensis Kwangtung Pine, Guangdong Pine Pinus lambertiana Sugar Pine Pinus leucodermis Bosnian Pine Pinus monophylla Singleleaf Pinon Pine, One-leaved Pine Pinus monticola Western White Pine Pinus mugo Mugo Pine Pinus mugo var. pumilio Mugo pine, Dwarf Mugo pine Pinus nigra Austrian Pine Pinus parviflora Japanese White Pine Pinus parvifola Pinus parvifola Pinus pinaster Maritime Pine, Cluster Pine, Turpentine Pine Pinus pinea Italian Stone Pine, Umbrella Pine Pinus ponderosa Ponderosa Pine, Western Yellow Pine Pinus pumila Japanese Stone Pine, Dwarf Siberian Pine Pinus radiata Monterey Pine Pinus resinosa Red Pine Pinus sabiniana Gray Pine, Foothill Pine Pinus strobiformis Southwestern White Pine, Mexican White Pine, Chihuahua White Pine Pinus strobus Eastern White Pine Pinus sylvestris Scots Pine, Scotch Pine Pinus thunbergii Japanese Black Pine Pinus virginiana Virginia Pine, Scrub Pine, Jersey Pine Pinus wallichiana Himalayan Pine, Bhutan Pine Pinus yunnanensis Yunnan Pine