Colorado’s fickle climate

A few weather observations this week. The Colorado climate never ceases to amaze me. September 19 and 20 had record highs for those dates, 96 and 94 degrees F respectively. Then on September 23, some low lying areas in Denver and open space areas on the outskirts had light frosts overnight. The following weekend another 90 degree F record high was set on the 26th. Be ready - temperatures can change on a dime or so it seems.

A visiting gardener told me this week that his cucumbers and other frost sensitive garden vegetables froze on Labor Day, September 6, during the last cold snap. His garden is in a low lying area in south-central Denver, not even on the outskirts of town. Clearing nights with radiational frosts combined with air drainage into low lying areas can catch plants earlier than most of the surrounding area.

As they say in real estate – location, location, location. This savvy gardener hedged his bets by cultivating plots in several community gardens that were unaffected. These low lying areas are bad bets for growing fruit trees.

It’s a good time to think about frost protection and season extenders now that fall is officially here. I admit to being biased but one of the best discussions I’ve seen on these topics is our CSU Extension CMG Garden Note 722, titled Frost protection and Extending the Growing Season. Review it for a refresher on how measures such as plant covers are used best


Diagram from CSU Extension CMG Garden Note 722.