plant diagnostic_database

                               Hawthorn (Crataegus spp.)                          


Affected Area:
  • Leaves                                                                   


Plant Information:


Hawthorns are members of the rosaceae family, are known for their pretty spring flowers and showy fruit in summer and fall. Most hawthorns grow to 20-30' tall & wide, with thorns up to 2" long.  Hawthorns are tolerant of many soils but they should be well drained, pH adaptable.  Douglas hawthorn which grows more like a large shrub is native to Montana.



Affecting Leaves:
Signs or Symptoms           Cause 
Blackened and wilting leaves Fireblight (Erwinia amylovora)
Pale green or yellow leaves Iron chlorosis
Caterpillars associated with webbing Fall webworm (Hyphantria canea) or Western tent caterpillar (Malacosoma californicum)
Chewing leaves Pearslug (Caliroa cerasi) or Forest tent caterpillar (Malacosoma disstria)
Leaves curled in spring Apple aphid (Aphis pomi)
Reddish spotting on upper surface/orange pustules, spiny eruption on underside Cedar-Apple Rust (Gymnosporangium rusts)
Affecting Stems, Twigs or Small Branches:
Signs or Symptoms Cause
Blackened, wilting, and crooked tips Fireblight (Erwinia amylovora)
White, wax-covered insects Mealybug (Pseudococcidae) or Wooly hawthorn aphid (Eriosoma crateagi)
Affecting Larger Branches or Trunks:
Signs or Symptoms                                Cause
Clear to white oozing or frothy malodorous liquid exiting from wounds Bacterial wetwood and slime flux


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