How to prune a weeping cherry tree first depends on whether the tree is natural or has been grafted. If you planted your tree, then you know it was grafted. However, if the tree was already growing, it is easy to tell whether it was planted there or grew naturally. Grafted trees will have a grafting knot just below the crown of the tree (where the branches spread from the trunk). There are different pruning procedures for grafted and natural trees.
Pruning a Grafted Tree
Pruning should always be done when the tree is dormant, which will occur during late fall or early spring. A dormant tree will not have any buds or open leaves. Pruning grafted trees is very important due to their tendency to create a snarl of branches right at the crown, which can make them more susceptible to disease during the cooler months when condensation is trapped between the tangled branches. Thus, begin at the crown to thin out this snarl and remove any branches that are growing straight up. In grafted trees, these vertical branches will not turn over to weep like the others. Secondly, make sure there are no branches touching the ground – trim tips of branches to at least six inches above ground level. Thirdly, prune any diseased branches and any branches in the center that are crossing or rubbing against each other.
Pruning a Natural Tree
To trim an ungrafted natural weeping cherry tree, start with the tips of branches and trim back any that are touching the ground to at least six inches off the ground. There will not be a center snarl on the crown to prune. Also, for natural weeping cherry trees, do not prune branches that are growing straight up. On these trees, they will turn over and becoming properly weeping branches with time. Finally, trim back diseased branches and look over the full shape of the tree. Pruning the tree should not only keep it healthy but also give it a symmetrical and aesthetically balanced appearance. Be sure the tree is shaped uniformly and remove any dangling branches. Keeping weeping cherry trees well pruned will help them to grow back fuller and healthier the following season.