I have an ornamental cherry tree that is healthy, but out of control, it hangs over two neighbors fences and I think they are tired of cleaning up the blossoms and leaves. Can I do a major pruning on it now...the buds are just starting to form. Thanks
"a major pruning...." not a good idea at any time. Proper pruning will not exceed 25% of the foliage or branchwork. Pruning now will cut off blooms and likely will initiate more re-growth than if it was done in early fall. Make sure to use proper pruning cuts and clean tools.
Prone to infection and sprouting awkward right angle replacement branches when headed back, mature Japanese cherries should hardly be touched at all. If the tree is poking into places where it cannot be allowed to reach, such as vehicle access routes that is too bad. If there is some pressing reason why the spent flower petals need to be cleaned up before they rapidly vanish on their own, that is too bad also. I was once gazing upon a street tree planting of locally very rare 'Pink Perfection' cherries and had a duffer with a flat top and suspenders pop out of his nearby, little square white house and ask me, eagerly, if I was there to cut them down. The fallen petals, you see, blew onto his lawn so he "had" to get out a blower and blow them away. In Japan there is a tradition of having a picnic and watching the petals fall from the cherry trees.