Prune Hollies, Crepe Myrtles, Butterfly Bushes & Blueberries Now

By C  Rae Hozer, Cumberland County Master Gardener

We have discussed pruning in general terms, now let’s get down to specifics and start naming names. Summer-blooming, woody shrubs can be trimmed after they go dormant in the fall until spring growth starts. In Tennessee that’s from November through about March, as long as no cuts are made while branches and twigs are frozen. Work on Hollies (species in the Ilex genus), Crepe Myrtles (or ‘Crape’ Myrtles if you prefer that spelling, of the Lagerstroemia botanic genus), Butterfly Bushes (Buddleia varieties), and Blueberries (American natives in the Vaccinium genus) today, if you like. Maintenance pruning promotes healthy and attractive plants but if the timing is slightly off, don’t get stressed about it. There’ll be no fatal consequences.

Reasons to prune include dead, broken, weak, old or unproductive stems and branches; a crowded center that blocks air flow and sunlight; as well as lop-sided growth which, if removed, will create a more pleasing shape.  

Standard equipment includes hand pruners, loppers and a pruning saw. Add a long-handled pole saw for cuts high in the canopy of taller shrubs/small trees such as mature Crepe Myrtles. Remember to use a spray bottle filled with rubbing alcohol to disinfect blades as you work. You know cuts made between nodes and large stubs heal slowly and that stubs expose plants to infection, decay or attacks from disease-carrying insect pests. Because electric hedge trimmers can create many ragged stubs, they are not a recommended tool for most pruning situations.

Many Ilex are evergreens, for example the red-berried Foster Holly commonly used by Tennessee landscapers. Winterberry Holly (Ilex verticillata) varieties drop their leaves in the fall. Winterberries are aptly named because they have attractive fruit throughout the cold season. ‘Afterglow’ (10 foot height and spread) and ‘Red Sprite’ (3 to 5 feet in height and width) are specimens with red berries. ‘Winter Gold’ (9 feet high x 8 feet wide) has bright, golden-orange fruit which seem to glow in sunlight. Visit the University of Tennessee Elmore Holly Collection at the UT Arboretum in Oak Ridge to see over 200 Ilex cultivars up close. Visit the web page http://forestry.tennessee.edu/hollies.htm to view an inventory of the collection’s holly specimens as well as a map of this research and display garden along with another map showing the four walking trails open to the public at UT’s Oak Ridge Arboretum site.

Cut out weak suckers at the base of Crepe Myrtles. Take off side branches on main trunks up to about four feet from the ground and remove higher branches which grow in toward the plant’s center. Cut above a bud or parallel to a supporting stem at the fork where a side branch grows. Flowers can be encouraged by nipping back about a foot at the end of branches that had blooms the year before, but severe pruning/topping of Crepe Myrtles is a bad practice which ruins the plant’s natural shape and produces ugly stubs. Some call this pruning method ‘Crepe Murder’.

Butterfly Bushes (Buddleia Davidii) may grow 12 feet high with a 12 foot spread. This plant rewards severe pruning. Cut stems back to ground level in winter. New shoots emerge from the roots in mid-spring and grow rapidly. Blooms are larger and more profuse on new growth.          

Blueberries grow slowly during their first 8 to 10 years. Just remove broken or damaged parts on young plants. At about nine years of age, look for thicker end twigs and heavier stems with scaly bark. These limbs don’t produce much fruit. Remove thicker, unproductive branch tips and central stems in late winter/early spring to renew fruit production.      

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.