General tree trimming advice typically recommends pruning a tree when it is dormant in late winter, but those trees that bloom in early spring are an exception. You should actually schedule tree trimming in the first couple of weeks after the blossoms drop from the tree in mid to late spring.
1. Improved Flowering
Most spring-flowering trees bloom on the last summer's new growth, so winter trimming will remove all of the flower buds and lead to little or no flowering that spring. You can schedule a bit of maintenance pruning during dormancy, such as cutting out obviously dead or damaged branches but save the major tree trimming service until after the flowering season ends.
2. Better Form
Being able to see the tree just as the blossoms fade and the new leaves are emerging can help your tree trimming service better prune to maintain a healthy form. Dead and damaged branches are most obvious at this time, as compared to in winter when there is no obvious growth. A tree pruned to good form is less likely to suffer wind or storm damages or to lose branches under their own weight.
3. Reduced Damages
Flowering trees, unless completely ornamental, often produce fruit that can weigh down and break overloaded branches. Trimming removes much of the fruit before it forms. It also gives your trimming service a chance to thin out parts of the tree that are too dense and heavy, which will also prevent damages from breakage or branches rubbing together.
4. Size Management
It's difficult to reduce the size of a tree once it has outgrown its allotted space. Annual trimming is a better strategy to help maintain the size of a flowering tree so that it doesn't become too large. Skipping even a single year's pruning can result in rapid growth and an overgrown tree. Once overgrown, it can take several years, often with reduced flowering, to trim it back to the desired size.
5. Less Mess
Fruit from flowering trees, even the extremely small fruits that ornamental varieties produce, can leave a mess in your yard, on sidewalks, or on cars parked under the trees. Trimming a spring flowering tree right after the blooming season will remove most of these fruits before they have a chance to fully develop. The result is a less messy tree that is still just as beautiful during the flowering period.
Contact a tree trimming service if you have further questions on spring-flowering tree maintenance.