Weather and Pruning
Weather patterns and temperature changes occur rapidly along the Front Range here in Colorado. I recommend nearly all pruning (with the exception of deadwood removal) to be performed in the dormant season. This practice allows the plant to produce the maximum amount of plant food for itself throughout the growing season. When branches are damaging structures, or creating a safety hazard (broken and hanging over targets, blocked school signs, crosswalk signs, creating habitat for unwanted visitors, etc.), it is best to remove the branches (live or dead) as soon as possible. This past spring Douglas County sustained a large amount plant death - branches, shrubs, whole trees - which was related to the frosts which occurred in the fall of 2019 and spring 2020. I had branch death at my own home, and some clients experienced dieback as well.
What can be done? In some cases, winter watering the plants during a period of warming temperatures would have helped keep some conifer branching sustained and alive. The uncontrollable factor, is how quickly the plants took up water on the warm days, only to have the water freeze inside their stems at night, and destroying conductive tissue in the youngest growth, and sometimes in the entire tree. Waiting to prune the tree until there is a sustained cold weather pattern will help. It will not be a cure all, but it will help. Pruning trees during a period of warm up in the winter may spark new growth, only to be eliminated by a massive temperature drop. I will be working on scheduling my winter pruning schedule in the coming 2 months, with a focus of waiting to prune any trees requiring live material removal until after the first frost, and during sustained cold weather. Please refrain from pruning during warm up periods this fall, as this may spark new growth right before a hard freeze or snowfall. This year has proven that can cause branch dieback. For tips on winter watering, check out CSU’s watering guide:
https://extension.colostate.edu/topic-areas/yard-garden/fall-and-winter-watering-7-211/