How to prune trees and shrubs

At a recent Muskogee Garden Club meeting, Master Gardener, Oyana Wilson said that the primary reasons to prune trees and shrubs include: Improve health, open branches to allow sun and air to move through the plant, increase fruit and flower size, and to keep the plant the shape and size that is best for its location.

Wilson said that gardeners should have an objective in mind before grabbing the tools. It is always a good idea to remove dead, diseased and broken branches as well as crossing or rubbing branches. A young tree or shrub is pruned to shape the plant’s future growth and an older plant is trimmed to rejuvenate it.

The best rule is to prune spring flowering shrubs and vines as soon as flowers fade and before May. 

Prune summer and fall flowering shrubs and vines in early spring prior to new growth.  There are exceptions, but the least desirable time to prune is immediately after new growth develops in spring. 

It is risky to prune in late summer or fall because pruning encourages new growth and tender growth can be damaged by an early frost.

Trees and shrubs should be examined annually.  Broadleaf evergreens, such as boxwood, cherry laurel, holly, photinia and nadina, should be pruned just before new growth in spring. 

Prune evergreen shrubs to control their growth and to shape them.

Hedges should be shaped with a rounded or slightly pointed top with sides tapering to form a wide base.  Try to make each cut just above an outward facing bud.  Never prune more than one-third of a plant’s branches or vines in any year. 

Overgrown shrubs can be gradually thinned from the center, removing the oldest branches first.

Renovating an old shrub can be done all at once, cutting entire shrub to within one-foot of the ground, or over a period of 3 years. 

To gradually thin a shrub, cut a few older stems down to the ground, leaving room for younger, thinner branches to mature.

When pruning trees, avoid cutting off the entire top. This method causes the tree to put out a large amount of weak, new, growth that may not be able to withstand winter storms.

Slower growing trees are structurally stronger and more resistant to storm damage.  Examples include: Bur Oak, Honeylocust, Shumard Oak, Hackberry, Kentucky Coffeetree, and Caddo Maple.  Fast growing trees damage easily, including: Silver Maple, Bradford Pear, Cottonwood, River Birch, Willow and Sycamore.

The correct way to cut a tree limb is called a three-step cut. The first cut is made on the bottom of the branch or limb, about one-fourth of the way through and 12-inches out from the final cut. The second cut is made all the way through the branch, from the top, a few inches farther out than the first cut, leaving a stub. Removing the stub is the final cut. This cut is made just outside of the branch collar. Go to the USDA Forest Service site for more information and pictures at http://tinyurl.com/77yhwsk.

Wilson said, “The best tools for pruning may be our own thumbnails. They are ideal for pinching out the tips of plants to control size, increase branching and blooms, and to prune suckers from tomato plants.” 

“Use hand pruners or shears for cuts up to one-half-inch thick,” Wilson said.  “Anvil shears will often crush part of the stem. If kept sharp, bypass pruners or shears do not do any crushing damage.  Loppers are for pruning branches from one-half to one and one-half inches in diameter,” said Wilson.

Whether you are pruning trees or shrubs, well-maintained and sharpened tools will make the job safer and easier.