Saturday, January 13, 2024, the temperature registered minus 20 degrees…add wind and it’s dangerous to be outside. So how does -20 degrees plus wind impact plants? A number of factors play into plant hardiness and surviving Wyoming winters.
The most important is planting USDA Zone 4 and Zone 3 Hardy Trees and Shrubs which are better equipped to survive Wyoming Wind and Arctic Cold Fronts. Wind, regardless of temperature, can dry out and kill tender twigs and less hardy branches. Zone 5 plants will only survive with good protection from those winds — maybe. An article(1) published in April 2021 in the University of Wyoming AgNews by Caleb Carter and Hudson Hill, provides additional information as to why the USDA Plant Hardiness Zone Map (which recently listed Laramie County as Zone 5a-5b) has its limitations when choosing plants for landscaping and gardening.
Tree roots are active year-round, always looking for a drink of water. In early October, it’s important to give trees and shrubs a good deep drink of water (no fertilizer). You’ll want your trees to go into winter well hydrated. If possible, give your trees and shrubs a drink when the winter weather warms above 45 degrees F. Watering goes a long way for tree survival by keeping tender twigs more hydrated and better able to withstand extreme weather and drying winds.
For additional information on the effects of severe freezes on trees, please check out this article(2) by Laurie Stepanek, published February 16, 2023, in the UW AgNews.
Sources and References:
“Use this tool to guide garden and landscape choices – but understand its limitations,” Caleb Carter and Hudson Hill, posted April 7, 2021, https://uwagnews.com/2021/04/07/use-this-tool-to-guide-garden-and-landscape-choices-but-understand-its-limitations/ ↩︎
“Understanding the Effects of Untimely Severe Freezes on Trees,” Laurie Stepanek, posted February 16, 2023, https://uwagnews.com/2023/02/16/severe-freezes/ ↩︎
Author: Catherine Wissner, Retired University of Wyoming Laramie County Extension Horticulturist and Laramie County Master Gardener