Deciduous Shade Trees. Prune shade trees such as oak, linden, and ash when they are dormant in winter. It's easiest to see the branching structure at this time of year, and you're less likely to spread diseases through the pruning wounds. As with nonblooming shrubs, avoid pruning them late in summer.
http://www.bhg.com/gardening/trees-shrubs-vines/care/what-to-prune-when/
1 For most trees, the best time for major pruning is late winter to early spring because wounds close faster. 2  Pruning in late summer and early fall may also stimulate new growth, which has little time to harden before cold weather comes.
http://www.csmonitor.com/The-Culture/Gardening/diggin-it/2010/0928/When-to-prune-trees-and-shrubs-Wait-till-after-the-leaves-fall
1 One exception to the no-fall-pruning advice is that you should remove dead, diseased, and damaged wood as soon as possible -- for tree health and your safety. 2  Take proper safety precautions at all times.
http://www.csmonitor.com/The-Culture/Gardening/diggin-it/2010/0928/When-to-prune-trees-and-shrubs-Wait-till-after-the-leaves-fall
When Not To Prune: Fall. Because decay fungi spread their spores profusely in the fall and healing of wounds seems to be slower on fall on cuts, this is a good time to leave your pruning tools in storage. Now that you know when to prune your tree learn the basics of tree pruning.
https://www.arborday.org/trees/tips/when-to-prune.cfm
When to Prune. This depends to a large extent on why you prune. Light pruning and the removal of dead wood can be done anytime. Otherwise, here are some guidelines, but recognizing that individual species may differ is important to remember.
https://www.arborday.org/trees/tips/when-to-prune.cfm
The best time to prune them is in early spring, just before they put on their growth spurt. You can do minor shaping and pruning at other times of year, too. Test Garden Tip: Save on holiday decorations by snipping a few branches for winter holiday greenery. 1  Check out our guide to pruning evergreens.
http://www.bhg.com/gardening/trees-shrubs-vines/care/what-to-prune-when/
Photos of the Day Photos of the day 02/08. 1  In early fall, pruning wounds close more slowly and plants are more at risk for fungal diseases than at other times of year. 2  For most trees, the best time for major pruning is late winter to early spring because wounds close faster.
http://www.csmonitor.com/The-Culture/Gardening/diggin-it/2010/0928/When-to-prune-trees-and-shrubs-Wait-till-after-the-leaves-fall
1 In early fall, pruning wounds close more slowly and plants are more at risk for fungal diseases than at other times of year. 2  For most trees, the best time for major pruning is late winter to early spring because wounds close faster.
http://www.csmonitor.com/The-Culture/Gardening/diggin-it/2010/0928/When-to-prune-trees-and-shrubs-Wait-till-after-the-leaves-fall
Fall isn't the right time to prune trees and shrubs.There are good reasons to wait till late winter or after the plants' leaves have fallen.
http://www.csmonitor.com/The-Culture/Gardening/diggin-it/2010/0928/When-to-prune-trees-and-shrubs-Wait-till-after-the-leaves-fall
If your purpose for pruning is to enhance flowering: 1  For trees that bloom in spring, prune when their flowers fade. 2  Trees and shrubs that flower in mid-to late summer should be pruned in winter or early spring.
https://www.arborday.org/trees/tips/when-to-prune.cfm
when is best time to prune trees
The best time to prune trees is early spring. The best time to prune tress is early spring.