NMSU branding

New Mexico State University

New Mexico State University

News Center

"False Spring" Leads to Winter Injury in Trees, Shrubs

LAS CRUCES - Unexpected warmer temperatures have tricked many New Mexico trees into breaking bud earlier than normal. That's bad news for trees and shrubs if there's another frost before springtime, said a New Mexico State University plant pathologist.

"This problem is called winter or Southwest injury," said Natalie Goldberg of NMSU's Cooperative Extension Service.

"Young, succulent tissues begin growing at a time when the plant should remain dormant, and they're damaged by a late frost."

Some injury symptoms include bark discoloration, patches of light yellow or green on what should typically be a brown trunk. Bark may start to crack or peel, and smaller twigs will die back from the end of the twig toward the trunk.

Affected trees include willows, various fruit trees and any shrubs that lose their leaves in winter. No action probably is the best approach to protect against winter injury, she said.

"You don't want to go out and start watering frequently or putting fertilizer on trees and shrubs," Goldberg said. "This creates a lot of energy for the plant to begin growing, but chances are, because it's so early in the year, we will have another frost."

Extra applications of water and fertilizer can begin once the frost danger has passed. Despite the weather's unpredictability, tree and shrub owners can get a typical "last frost date" for their particular area from the county Extension agent, Goldberg added.