February is generally an ideal time of year for pruning. However, now is not the time to prune certain species of plants – that is, if you like flowers. In the plant world, each species has its own rhythm for growth and reproduction. Cutting back some plants right now will remove their ability to flower this season. The reason is that these species bloom on old growth. If last year’s stems are removed, then so are this year’s flowers.
Early spring flowering trees and shrubs are a perfect example. Dogwood, forsythia, rhododendron, azalea, viburnum, weigela, pussy willow, pieris, daphne, flowering quince, ninebark and others bloom on old wood from last year’s growth. It makes logical sense since many of these species go straight into bloom after breaking winter dormancy with no growth period for new buds to grow. There are few exceptions with cultivars that are selected for their ability to rebloom. However, even in the reblooming series Encore azaleas, it is not recommended to prune in the winter because that first flush of spring blooms will be lost.
Hydrangeas are notoriously confusing when it comes to pruning. Within the genus are species that bloom on last year’s growth, such as the mophead types (Hydrangea macrophylla), and species that bloom on new growth. Clematis is another genus that has members with blooms on old growth, members with blooms on new growth, and some that have a combination of both. The good news is that pruning at the incorrect time is not likely to injure the plant. One season without blooms can be a lesson learned. Both hydrangea and clematis factsheets are available at hgic.clemson.edu.
So when is the best time to prune something that blooms on old wood? Prune them ‘immediately’ after they bloom. I use the word immediately lightly, as it is not a severe window of opportunity, and sometimes life happens. I find these plants the most difficult to remember to prune because of my schedule in late spring/early summer. As long as the plant is pruned early enough to put on sufficient new growth in the growing season, it will bloom the following year. For information and a list of plants that bloom on old wood, visit the online factsheet HGIC 1053, Pruning Shrubs.
Adam Gore will give a free, virtual presentation on Spring Lawn Preparation at 11 a.m. March 1. Visit bit.ly/ClemsonLawnPrep to register. Registration is open for the 4H Pullet and Laying Flock Projects. Contact the Greenwood County 4H Agent, Lucy Charping, at email@example.com for information.
County agents and staff are available to assist clients through telephone, email, and virtual platforms. Contact me at firstname.lastname@example.org, or 864-889-0541. The Greenwood County Extension office is accepting soil samples, for electronic payment only, via a drop box outside the office at 105 North University Street. Complete the soil form, attach it to your soil bag, and drop both into the box. We will contact you for electronic payment over the phone. No cash or check payments can be accepted in the drop box! Alternately, you may mail your sample, soil form, and check or money order directly to the lab address on the form. Call 864-223-3264 with soil sample questions. Visit our Facebook page at facebook.com/GreenwoodCoExtension where we will be posting timely information.