Birch > Leaves > Leaves wilt and turn yellow or brown
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Bronze birch borer
- Eventually twigs and then branches dieback starting at the
top of the canopy and progressively working its way down
- Foliage at top of the canopy first becomes sparse
- Raised lumps or ridges can be seen on the trunk and branches
- D-shaped exit holes can eventually be observed on the trunk
- S-shaped galleries can be seen under the bark
- Preferred hosts are European white birch and whitebarked Himalayan birch; paper birch, gray birch are also attacked; river birch is rarely infested
- More information on Bronze birch borer...
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- Foliage wilts and sometimes turn brown around the edges
but more commonly turns a dull, gray-green color
- Dried brown to gray-green leaves hang on the tree or more commonly, foliage drops prematurely and litters the ground
under the tree
- Severe drought stress may cause dieback of individual branches starting at branch tips
- More information on Drought damage...
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Armillaria root rot
- Infected trees have poor growth, dead branches in the upper canopy, undersized and/or yellow leaves
- Flat white sheets of fungal growth (mycelia fans) grow between the bark and sapwood at the base of infected trees
- Thick black, shoestring-like fungus can sometimes be seen under the bark, around roots and in the soil around the base of the tree
- Wood is decayed, white, soft and spongy, and this may extend from the base of the tree well up into the trunk
- Clusters of honey-colored mushrooms may grow at the base of the tree in fall
- More information on Armillaria root rot...
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Polyporus squamosus, Laitipors sulphureus, Fomes
fomentarius, Phellinus igniarius, Piptoporus betulinus
- Canopy may show no symptoms, or may have small yellowing leaves or dead branches depending on the extent of the decay
- In cross section of the trunk, the wood at the center is discolored, soft, crumbling, stringy or spongy
- Fungal fruiting bodies arise along the stem; often near a pruning wound, crack or other wound
- Many colors, shapes and sizes of fruiting bodies may be seen
- More information on Heart rot...
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Ganoderma root and butt rot
- Leaves are smaller in size and turn yellow earlier than normal
- Canopy appears thin with few leaves and multiple dead branches
- Fungal conks, a semicircle shelf fungi, can be found from the base of the tree up to 3 feet high on the trunk
- Conks are reddish-brown and shiny on top, white and porous underneath; a rim of white may be visible on the edge of
- Infected wood at the base of the tree is white, soft, stringy
- Infected trees frequently break or fall over in storms
- More information on Ganoderma butt rot...
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- - NO PHOTOS AVAILABLE -
Leaf and shoot blight
- Leaves wilt, die and remain attached to the branch when the canker completely girdles the branch
- Infections on young shoots cause branch tips to curl over in the form of a Shepard's crook
- Black sunken cankers occur on bark of infected branches
- Occurs only on yellow birch
- More information on Leaf and shoot blight...
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Coral spot canker
- Common on trees stressed by drought, recent transplant or
- Dead branches and twigs are often first observed in early spring
- Sunken dark brown area on branch that is often cracked or has a ridge at the edge
- Raised cushion-like bumps on affected branches, may be cream
to orange or red, turn black with age
- More information on Coral spot canker...
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Perennial nectria canker
- Dead branches and twigs killed by girdling cankers
- Sunken target shaped cankers on main trunk or branches
- Cankers do not have bark and raised ridges of wood occur in target-like rings within the canker
- Red to reddish orange raised cushion like bumps can occasionally be seen on the edge of the canker
- More information on Perennial nectria canker...