So there is a nice old crab apple tree in the back yard neglected for some years, badly in need of a pruning. Bought the house last spring and renovated all spring/summer and pruning the tree was low priority then. I was of the impression that when a tree or shrub is dormant it is less prone to shock and it wouldn’t be a bad time to prune. After doing a brief search almost all articles state that late fall is a bad time to prune, but I do not see a lot of reasons given.
It sits in direct view of a nice big window in front of the kitchen bar and I’ve been thinking dressing it up with lights for the winter would give me something pretty to look at during dark breakfasts and dinners. Thing is its a tangled mess of branches and wrapping it with lights seems a little challenging in that state.
I am in Alberta, so it is nearly winter at this point, temperatures freezing at night and soon most days will be below freezing too. I do not see a lot of buds formed. So, arborist dopers, will it really harm the tree to prune it at this time?
Here;s a great explanation of what occurs during different times of plant growth/dormancy. Tells of the hormones and such that flow up/down tree affecting growth and how the intake/storage -v- output of the ‘energy chemicals’ from roots in growing period is different than the time of tree going dormant. Tree has a two-way street in its cellular structuring, kinda, and seasonal changes affect which way stuff moves around in tree’s overall mass.
Basically, pruning too early can/will cause new growth to ‘erupt’, only to be killed by soon-to-come coldest temps, etc if it has no chance to ‘harden’ against the cold. Bad overall for the vigor of tree. A tree going dormant is basically sending ‘energy reserves’ down to roots to await new growing season when the new growth will be able to handle the warming weather in a healthy manner.
A bit more complicated, of course, but that is it in essence - prune too early on dormancy-side of things and you are more prone to get lots of ‘backbudding’/early eruption of waiting-to-grow buds which will not be around for the next growing season. Pruning in late-spring/summer typically only gets minimal eruption of backbudding and plant remains more or less ‘balanced’ in root-v-above-ground stuff (hormonally speaking). Hope that makes sense and/or helps you understand, **FluffyBob
You might also learn a thing or two about keeping your crabapple in peak form/shape/health by going to the “Articles” index at top of article’s page and reading his specific thoughts on crabs - though mostly focused on bonsai principles, it also applies to getting better form/fuction of a ‘free-range’ crabtree overall, IMHO.**
Its best to wait until you are absolutely certain that tree is dormant or those buds/leaves just might try and erupt/grow, just to be killed sooner than later. That leaves a weaker tree next growing season. In a nutshell anyways… HTH
