Mother’s Day Freeze 2015 – What was affected?

Mother’s Day 2015 brought with it a chilly surprise – freezing temperatures and accumulating snowfall. Perhaps most caught off guard were landscapes with rich green lawns and trees and shrubs with bountiful foliage.

Much of Northeastern Colorado had an abundant amount of natural precipitation in 2015, resulting in early spring succulent growth. On May 9th the temperature dipped to 27 degrees – tying a record set back in 1946 and freezing newly emerging plant foliage (the amount of damage is predicated on how well established the foliage was when the storm hit).

However, it was not cold enough to freeze stems. Most plants will in fact re-foliate, but will need to pull reserved energy to do so. This will essentially weaken trees and shrubs – making them prey for wood boring insects to infiltrate.

Trees are seeing prior damage due to the November Freeze of 2014. You might remember the high was 64 degrees on November 10, and then dropped to a record low of -13 degrees on November 12 – a 77 degree decrease in temperature. This was the third largest temperature drop ever recorded in the Denver area – February 1951 saw the greatest at 80 degrees; January 1961 came in second at 78 degrees.

Again, plants will re-foliate from dormant leaf buds after the Mother’s Day freeze. The process will take between two to four weeks and the trees/shrubs may have a more sparse appearance for the remainder of 2015 along with more dead twigs and branches.

Some trees/shrubs which might be affected by the Mother’s Day Freeze are:

Shrubs & Vines: Siberian pea shrub, Virginia creeper


Evergreen (needle bearing), Blue spruce

Deciduous – leaf bearing: Autumn Purple Ash, Catalpa, Elm (some species), Goldenrain Tree, Green Ash, Hackberry, Honey Locust, Maple (some species), Oak (some species), Sumac, Sycamore, Black Locust

Some trees/shrubs which might be affected by the November Freeze are:


Evergreen, conifer (needle bearing), Arborvitae, Junipers, Evergreen (leaf bearing), Barberry, Boxwood, Holly, Manhattan Euonymus, Pyracantha

Deciduous – leaf bearing: Buckthorn, Burning Bush, Privet (Lodense and Golden Vicory), Rose, Spirea, Weigelia


Deciduous – leaf bearing: Cherry, Plum, Silver Maple, Autumn Blaze Maple

Austrian Pine, Ponderosa Pine, Spruce (needle bearing)