Eco-Answers from the Pros: Borers in Amelanchier

Has anyone had experience with borers in Amelanchier canadensis? If yes, how to treat and what’s the prognosis for the survival of these trees.

Serviceberry or Shadblow rarely has insect problems. Amelanchier canadensis is a multistemmed shrub that can reach 20 feet high. According to Michael Dirr (1998), a recognized authority on woody plants, A. canadensis is often confused with A. arborea, a multi-stemmed tree.

The borers could be a wide variety of twig and stem borers of moths, beetles, or sawflies. Most are attracted to trees or shrubs that are stressed. I had a few nice specimens of shadblow when I worked at Mass Audubon and never had any serious insect problems that warranted control.

Borers are USUALLY a sign of some type of environmental stress like drought, heat, sudden drop in temperature, or a soil nutrient problem. Keep the tree watered during drought and, if possible, cut out infested branches or branch portions. The plant will recover from borer damage if it is a moderate to low infestation. Don’t over fertilize with an inorganic fertilizer. Use slower releasing organic fertilizer and keep it watered during droughty conditions for borer control. Reducing the environmental stress will increase the plant’s defenses over time.

Bruce Wenning, Horticulturist, The Country Club, Brookline, MA

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