There is no rule that states Japanese Maples must be pruned for their own good. The best pruning of a happy JM would be limited to the removal of the deceased interior branches.

Pruning them should only be done as needed to make any corrective cuts to improve their health and appearance or fit in with the neighboring plants. It is an aesthetic mode of pruning not a must be done kind of thing.

Winter when the trees are completely bare and when you can see their bone structure is a good time to prune. Some purists may specify the exact dates. Sometime over the winter works for me. Follow any branch you want to remove to where it connects to the next branch, Cut there. You don't want branch stubs and a bunch of cut branch tips.

trees never need to be pruned .... they are pruned for a reason ... lets call it a goal ...

what would be your goal in pruning them???

are they scraping the house?? ... at least we dont have to worry about them falling on the house and crushing it ... lol ...

are they blocking a walkway ... blocking a view?

etc.. etc.. etc ...

we do prune out damaged material .. are you aware of any such???

ken

Thank you Ken and Christopher, for your answers.

The reason is esthetics.

lol... i dont prune in winter.. mostly becasue there is 2 feet of snow.. and wind chill below zero.. so screw that ... lol ...

maples bleed in spring when cut too early.. think maple syrup ... so you avoid such .. [yeah i know this it the asian maple.. maybe it miso???.... its a joke.. just laugh and read on .....]

and otherwise.. prune whenever you want ... just like the tree trimmers you you area do ... if a branch breaks.. prune it off ...

websites which claim dates like mentioned above.. may be a bit too pompous for reality ... besides the fact that unless you are in their garden.. does it really even apply to you.. hence the story of my MI ...

there are some things with certain plants.. and certain bugs or diseases that require more precise timing .. so its good you asked ..

soooo... whats your GOAL??

ken

As the previous posts have mentioned, pruning of Japanese maples should be approached with a very light hand. Winter is a good time IF any pruning is needed but do not wait too long into the season. Once the sap starts to rise in late winter, it can get messy. And never remove more than a fifth of the canopy, if you should decide to prune (photos don't show any compelling reason AFAICT). It can result in excessive leggy or whippy growth the following spring.

Summer is also an excellent time to prune........should any pruning be necessary.

btw, unless you are an experienced pruner, I'd hire this out to a professional. Too many trees are ruined aesthetically by inexperienced pruners and JM's are far too valuable to be mangled.

Had to look AFAICT up...."as far as I can tell."

Beautiful trees.

I do not think they need pruning

In my opinion the only time you do not prune is when it will affect the next year flowers . Since Maples do not have any flower (that people recognize as flowers) just about any time would be acceptable. Trim the minimum that is necessary. It a large amount of the tree needs to be removed do it i small amounts of several years.

Note: I think maples are significantly underrated as a flowering tree, and equal tp accepted flowering trees like crab apples. I think the main problem is the flower so early most people are inside in the warmth, and don't look out of the windows.

"In my opinion the only time you do not prune is when it will affect the next year flowers . Since Maples do not have any flower (that people recognize as flowers) just about any time would be acceptable."

There are real and valid times recommended for pruning trees depending on species so I would disagree on a blanket assessment depending solely on flowering attributes. For example, maple sap starts becoming active in late winter so pruning then or into spring but before bud break (when sap movement slows) can lead to excessive 'bleeding' or sap leakage. Oaks should never be pruned from late spring through summer, as that's when oak wilt is most active. And fruit trees that are vulnerable to diseases - so most of them - should not be pruned during the rainy season when the diseases are too easily spread by wind and rain, often making winter and early spring the least desirable times to prune.

It is also important to understand that when you prune affects the results. Pruning stimulates growth, especially dormant season pruning, so heavy pruning at that time can result in lush vegetative growth that negates the pruning entirely, produces excessive epicormic growth (water sprouts) and can impede flowering and/or fruit production. Summer pruning will result in less vigorous regrowth so an ideal time for canopy thinning and fine tuning.