Superior Pruning Techniques

By C  Rae Hozer, Cumberland County Master Gardener  March 6, 2009

According to Random House Publishing (at their web site www.randomhouse.com ) the phrase ‘a cut above’ means ‘a level or grade above; superior to’. Pruning techniques that are a cut above involve smooth, slanted cuts made about 1/4 inch above a live bud or cuts close to the narrow part of the ‘V’ formed where a limb attaches to the trunk and where twigs grow from  supporting branches. Remove dead wood similarly– trim back to a live branch or cut just above a green bud. These recommended pruning points have fast cell growth. Cuts made there will close (heal) rapidly, unless the stub left above the growth point is too big.

Quick healing is important to plant disease prevention. The longer a wound on a woody stem remains open, the greater the risk that infection or rot will enter. The problem can feed back into the main structure and weaken the entire tree or shrub. Rough edges, cuts with flat faces where rainwater collects and leaving large stubs are all poor pruning practices that encourage disease and decay. Ragged wounds and leaking sap attract harmful insects. Don’t count on  pruning paint or other types of wound dressing for a remedy. Tests by horticultural scientists have shown such surface treatments don’t effectively prevent infection or keep insects away.

Be sure to use sharp, properly adjusted tools. They make better cuts. Do not wiggle hand pruners around during the cut. That produces ragged edges. Pruning cuts must be straight and smooth. Hold loppers or saws at an angle that won’t rub and damage the bark on supporting branches. If plant material is more than 1/2 inch in diameter, use a saw to remove it.

In any pruning discussion it helps to know plant terms like ‘nodes’, ‘internodes’, and about various bud types. A ‘node’ is a spot where leaves grow along a stem or branch. At plant nodes, new growth is rapid. The space between two neighboring nodes is an ‘internode’. Along the internode area cell growth is slower. Cutting on an internode at a distance from the closest node leaves an undesirable stub. Buds grow to become different plant parts. Some buds form shoots that become side branches or extend the tree top upward (axillary or lateral buds, terminal buds) or make new foliage (leaf buds). Others produce blossoms. (You guessed it– flower buds.) Buds may grow anywhere along a branch but often develop under leaf stems and at branch tips.    

The terminal bud at the end of a branch is vigorous and dominant. It sends out plant hormones to suppress development of buds below it on that branch. Removing the branch tip and terminal bud stimulates new side shoots below the pruning cut. Tip pruning may produce a bushier plant. The strongest growth point will be the bud just below the cut. After pruning, the branch usually  grows the way that bud points. Cut above outward-facing buds to develop openness in the middle of the plant. Most shrubs and trees benefit from more sunlight and better air circulation at their center. Fewer middle branches promote good blooming, too. More flowers lead to increased fruit, berry and nut production on woody species raised for that purpose.

Check out the new University of Tennessee web site Gardening.Tennessee.edu

Scroll to mid-page. You will see ‘>UT Gardening Publications (free!)’ Click on that line. Choose ‘Landscaping’ (or click here) then select the publication ‘Pruning Landscape Trees, Shrubs and Ground Covers PB1619’ under the title ‘Maintenance’. Get a 15-page pruning booklet with lots of helpful color pictures to view on your computer screen or print at home, if you prefer.

Plateau Gardening is written by Master Gardeners for those tending home landscapes and gardens in Tennessee’s Upper Cumberland Region. Contact UT Extension Cumberland County, P.O. Box 483, Crossville, TN 38557, (phone 931-484-6743) for quick answers to specific questions, free publications, or to learn about becoming a Master Gardener. Email comments or yard and garden inquiries to Master Gardener Rae, mgardenerrae@frontiernet.net.