Alder decline - Symptoms:
Small leaves, thin foliage, necrosis at the lower trunk and yellowing.
Cause is unknown.
Diseases Alnus cordata
Leaf curls (Taphrina tosquinetii):
Extremely wavy leaves caused by fungi. The fungus should be controlled
before an outbreak.
Canker (Nectria galligena):
Fungi that leads to the breaking off of bark. Affected twigs and
branches should be removed and burned. If the trunk is affected,
then an expert should be called to remove canker.
Classification Alnus cordata
Height: 8 - 25 m (26 - 82 ft)
Leaf: rounded to wide ovate, serrated
Flowers: March - April, male catkins reddish, female red
Fruit: woody and cone-like, dark brown
Branches: smooth, shiny, brown red
Bark: smooth, grayish green, lenticels
Root: shallow roots
Habitat: sun to half-shade
Soil: sandy-loamy to loamy
ph-value: acidic to alkalescent