Wood Decay
Limb and
125 host plants
Last updated
Data Coverage 3 of 6 dimensions
Look for moist, soft, or spongy wood that's lighter in color than healthy wood, sometimes with fine black lines running through it. On birches and maples, you'll spot woody, hoof-shaped conks (fruiting bodies) growing from trunks or branches; they may have a smooth gray surface or become rough and cracked with age. These fungal structures signal that decay has been progressing inside for months or even years. The damage is often hidden until a branch suddenly fails or the tree shows obvious signs of weakness.
Wood decay fungi enter through wounds: pruning cuts, storm damage, sunburn cracks, or mowing injuries. Once inside, they spread slowly through heartwood and sapwood, weakening the structural integrity of branches and trunks. The key to managing this is prevention: avoid large wounds, make clean pruning cuts near the branch collar, prune when branches are small, keep mower equipment away from the trunk, and don't overhead-irrigate onto the bark. If you see conks or suspect decay, inspect the tree with an arborist to assess stability and avoid property damage.
Quick Reference
Causal Agent
Limb and
Host Plants
125
Management
Cultural Controls
- Help prevent wood decay by using cultural practices that promote tree growth and vigor while minimizing injuries that expose wood.
- Irrigation water, especially from sprinklers, should not wet the trunks.
- Mowing equipment should not injure the roots, crown, or lower trunk.
- Make pruning cuts adjacent to, but not into, the supporting branch, and prune when branches are small to enhance callus formation and wound healing.
- Reference Guglielmo, F., Michelotti, S., Nicolotti, G. and Gonthier, P. 2012.
- Population structure analysis provides insights into the infection biology and invasion strategies of Kretzschmaria deusta in trees.
Host Plants (125)
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 Betula alleghaniensis Yellow Birch Betula davurica Asian Black Birch, Dahurian Birch Betula glandulosa Dwarf Birch Bog Birch, Scrub Birch Betula lenta Sweet Birch, Cherry Birch, Black Birch Betula maximowicziana Monarch Birch Betula nana Dwarf Birch, Bog Birch Betula nigra River Birch, Black Birch Betula occidentalis Water Birch, Western Birch, Red Birch, River Birch, Black Birch Betula papyrifera Paper Birch Betula pendula European White Birch Betula platyphylla Asian White Birch, Manchurian Birch Betula populifolia Gray Birch, Fire Birch Betula pubescens Downy Birch, Moor Birch Betula utilis Himalayan Birch, Bhojpatra, Indian Paper Birch Betula utilis subsp. albosinensis Chinese Paper Birch, Chinese Red Birch Betula utilis subsp. jacquemontii Whitebarked Himalayan Birch Corylus americana American Hazel, American Filbert Corylus avellana Common Filbert Corylus chinensis Chinese Hazel Corylus colurna Turkish Hazel Corylus cornuta var. californica Western Hazel, California Hazel, Western Beaked Hazel Corylus heterophylla Siberian Hazelnut Asian Hazel Larix decidua European Larch Larix gmelinii Dahurian Larch Larix kaempferi Japanese Larch Larix laricina Tamarack, Eastern Larch, American Larch Larix occidentalis Western Larch, Western Tamarack Larix russica Siberian Larch, Russian Larch Prunus americana Wild Plum American (Red) Plum August Plum, Goose Plum Prunus armeniaca Apricot Prunus avium Sweet Cherry Prunus besseyi Sand Cherry, Western Sand Cherry Prunus blireiana Blireiana Plum Prunus caroliniana Carolina Cherrylaurel American Cherrylaurel Prunus cascade Prunus cascade Prunus cerasifera Cherry, Plum Prunus cistena Purpleleaf Sandcherry Redleaf Sandcherry Cistena Sandcherry Cistena Plum Prunus dream Prunus dream Prunus emarginata Bitter Cherry, Wild Cherry, Quinine Cherry Prunus first Prunus first Prunus fruticosa Steppe Cherry, European Dwarf Ground Cherry, Mongolian Cherry Prunus glandulosa Dwarf Flowering Almond Prunus ilicifolia Hollyleaf Cherry, Holly-leaved Cherry Prunus laurocerasus Cherry, Laurel Prunus lusitanica Portugal Laurel Prunus maackii Amur Chokecherry Amur Cherry, Manchurian Cherry Prunus mume Japanese Apricotc Japanese Flowering Apricot Japanese Flowering Plum Prunus newport Newport Flowering Plum Prunus okame Okame Flowering Cherry Prunus padus European Birdcherry Common Birdcherry Prunus prostrata Rock Cherry, Mountain Cherry Prunus sargentii Sargent Cherry, Sargent's Cherry Prunus serotina Black Cherry, Rum Cherry Prunus serrula Birchbark Cherry, Paperbark Cherry, Tibetan Cherry Prunus serrulata Japanese Flowering Cherry Prunus snow Prunus snow Prunus subcordata Klamath Plum, Sierra Plum, Pacific Plum Prunus subhirtella Higan Cherry Prunus subhirtella var. autumnalis Autumn Flowering Higan Cherry Prunus tai Prunus tai Prunus virginiana Prunus virginiana Prunus virginiana var. demissa Western Chokecherry Prunus virginiana var. virginiana Common Chokecherry, Eastern Chokecherry Prunus yedoensis Yoshino Cherry, Somei-yoshino Cherry, Tokyo Cherry Quercus phellos Willow, Oak Salix alba Salix alba Salix babylonica Weeping Willow Salix caprea Salix caprea Salix integra Salix integra Salix magnifica Magnolia-leaf Willow, Magnificent Willow Salix matsudana Salix matsudana Salix pentandra Laurel, Willow, Bay Willow Salix phlebophylla Skeletonleaf Willow Salix purpurea Purpleosier Alaska Blue Willow Salix scouleriana Scouler's Willow Tsuga canadensis Canadian Hemlock, Eastern Hemlock Tsuga canadensis var. pendula Weeping Hemlock Tsuga diversifolia Northern Japanese Hemlock Tsuga heterophylla Western Hemlock Tsuga mertensiana Mountain Hemlock