Pruning for healthy, atteracftive and productive plants

Published on Wednesday, 25 December 2013 23:58 - Written by By Keith Hansen Keeping It Green

At this time of year, as our trees and shrubs enter dormancy, homeowners often think about pruning their plants. Improper pruning can destroy in a few minutes the beauty, grace and vigor of a plant that nature has worked for years to create. It is better not to prune at all than to do it incorrectly.

Proper pruning of trees and shrubs involves art and skill. The artistic part is to prune plants so the result is pleasing to the eye — a compliment to the yard and landscape. One only needs to look at the thousands of butchered crape myrtles across the South to understand the lack of art applied to this particular plant.

Skill and technique comes from understanding a few basic rules, and applying them correctly through practice.

First of all, make sure you have a good reason to pull out the pruning saw or clippers. If you are pruning for no other reason than just because it’s that time of year, put your gear up and find another outlet for your energy.

Plants may need pruning for any number of reasons: training young plants to be structurally strong, to encourage fruit or flower production, to correct or redirect growth, and remove dead or diseased wood.

In general, pruning cuts should be made just above a growth point (dormant bud) or at a branch union. Never leave stubs if at all possible because the remaining stub will die and promote decay back into the remaining branch. This is especially important when pruning trees.


Some Common Plant

Pruning Questions

Hydrangeas — Most hydrangea varieties bloom on previous season’s growth. Growth that was produced in 2013 will bear the flowers in 2014. This is true for the common mophead or lacecap hydrangeas with large blue or pink flower heads, and for oakleaf hydrangeas.

These should be pruned after blooming. Because the hydrangeas bloom over a long period of time, you may need to selectively prune shoots that have already bloomed while leaving others to finish blooming. If you prune hydrangeas back to the ground in winter, you will eliminate all flowers the following year.

As with many things, there are “exceptions to the rule,” and many of the newer reblooming hydrangea varieties (such as the Endless Summer and Forever & Ever series) have the capacity to bloom on current season’s growth as well as previous year’s shoots. However, even these should not be cut to the ground in the winter, or else bloom will be delayed.

If your hydrangea has overgrown its spot, remove the oldest shoots to the ground, leaving the younger shoots to fill in. Prune remaining shoots after blooming, leaving just two to four pairs of buds. Keep in mind that it will eventually get large again, so you may need to move it to a new location where it can grow without severe pruning.

Azaleas — Most folks realize that azaleas, like hydrangeas, bloom on previous season’s growth, so hold off pruning until after spring bloom. However, you can do selective shoot removal in the wintertime without messing up spring bloom. For example, strong, vigorous limbs shooting up above the rest of the planting can be removed at any time during the year.

Just like the reblooming hydrangeas, reblooming azaleas (Encore is the most popular series) also will bloom again on current season growth. Just don’t prune heavily now, or you will miss the first spring bloom.

Roses — Modern roses, which bloom throughout the summer, produce flowers on current season growth. Therefore, to stimulate strong, vigorous growth, most roses are pruned in early to mid-February. An exception is for roses that bloom only once a year in the spring. Some antique roses and climbing roses fall into this category, like Lady Banks rose. Once-blooming roses are pruned after they finish blooming in spring.

Fruit Trees — Prune fruit trees and grapes in January and February. Research has shown that fall pruning of some fruit trees can promote earlier blooming and thus increase the risk of frost damage to next year’s crop.

Crape Myrtles — Mentioned earlier as examples of nearly universally poorly pruned plants, crape myrtles take a beating every winter when cut mercilessly back by well-intentioned, but misinformed, gardeners. Somewhere along the line of gardening history, it became fashionable to severely cut back crape myrtles. Perhaps some thought it was a cultural necessity for the health of the plant. Others may have felt it enhanced blooming. Some see others cutting back and must feel that it’s just one of those things that must be done each year. Still others may have planted a large cultivar where a small one should have been planted, and have to cut it back every year to make it fit into its location.

Speaking of making it fit, if you find yourself slavishly pruning back a plant every year, whether tree or shrub, just to make it fit into a certain spot, you should seriously consider removing it and redesign that area with plants whose mature size naturally fills in the area without additional pruning maintenance.

Back to crape myrtles. Besides the summer flowers, one of crape myrtles’ outstanding features is the beautiful sinuous trunks and limbs with the attractive exfoliating (peeling) bark. A well-trained crape myrtle can be just as beautiful in winter as in summer when in full bloom. Annual topping of these plants ruins the winter aspect of these great plants. The resulting knuckle of wood on top of the trunks with short stubs sticking out is an eyesore to many.

University research has also shown that pruning crape myrtles in the fall through early winter can result in an increase in freeze injury and dieback.

There is a crape myrtle sized and shaped to fit any landscape situation. Pruning should only accentuate the natural shape and character of the plant, and to remove crossing, rubbing and crowded branches. Small twigs and dead wood along with old seed heads can also be removed on smaller, younger trees.

If you’d like further reading on what many across the South refer to as “crape murder,” read an interesting web-based article at http://aggie-horti cations/stopthecrape.html

A reference book that I have found useful for tips and instructions on pruning many different trees, shrubs and vines is “Sunset Pruning” by Susan Lang — Sunset Publishing. A large selection of plants is listed in encyclopedia form, with good details on training and pruning.

Keith Hansen is Smith County Horticulturist with the Texas A&M AgriLife Extension Service. His web page is http://EastTexasGardening. His Blog is Texas A&M AgriLife Extension Service educational programs are open to all individuals without regard to race, color, sex, disability, religion, age or national origin.