Growing Green

By Robin Trott, Extension Educator

Emerald ash borers (EAB) typically have a one-to-two-year life cycle, living under the bark of ash trees and causing damage to the tree’s outer sapwood and vascular tissue. This damage disrupts the flower of water and nutrients, potentially leading to the tree’s death in as little as two to four years.

While subzero temperatures can be detrimental to EAB larvae, with research showing that temperatures below minus 30 degrees for 24-48 hours can significantly reduce their numbers, warmer winter temperatures pose a threat. In Minnesota, colder temperatures have historically slowed the progress of EAB compared to other states.

With warmer winters, EAB larvae are more likely to survive, as they can feed over an extended period. This may result in a higher number of larvae emerging after one year instead of the usual two-year cycle. Additionally, drought conditions during previous growing seasons can worsen EAB damage, as stressed trees become more susceptible to pests and diseases.

The lack of snow cover is another concern, as snow serves as an excellent insulator protecting tree roots by moderating soil temperatures. Without sufficient snow cover, sudden extreme drops in temperature may lead to increased root death.

To find out more about Emerald Ash Borer, visit https://www.mda.state.mn.us/eab.

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“The best thing about bugs is their lack of self-consciousness, also the ability to fly doesn’t hurt.” ~Dov Davidoff