Instances of bad pruning jobs illicit violent images: crepe murder, hack job, and butchering. Maybe we know that when we see the broken branches, wounds in the bark, topped crowns, and exposed splinters we know something has gone wrong. Pruning is one of the most basic horticultural techniques, yet it stumps even the best gardeners sometimes. Part of this is the intuitive nature of the practice, but sometimes it is a misunderstanding of the science and reasoning behind why you should (or shouldn’t!) prune. We’re tearing down the crime scene tape: let’s talk about winter pruning.

Tony Avent, of Juniper Level Botanic Garden, pruning muscadine grapes- Photo by Amanda Wilkins

Setting the Scene

There are a few general things to keep in mind when assessing a pruning job. The most important things to ask yourself are: “What am I accomplishing by pruning this plant? Does this plant need to be pruned? Or do I just think it needs to be, based on what I see others doing?” There should always be a reason for pruning. If you are not sure, it is okay to leave the plant alone!

Winter is a great time to do most pruning jobs in the landscape in the Southeastern United States. Our climate is mild enough over the winter that the wounds we create by pruning do not pose an issue with the health of the plant. Most plants are dormant and pruning does not generally cause much sugar or water loss. It is also a great time to see the overall architecture of deciduous plants, so you can assess structural needs the plant might have.

Don’t Get Caught Red-handed

Don’t use dull tools: Like the violent images suggest, using a dull tool is a great way to cause injuries to your plants. Make sure to sharpen tools when appropriate and use the right implements and angles for sharpening. Clean sap and debris off of blades before storing your tools to reduce degrading the metal.

Don’t make a cut you can’t handle with the tool you have: It can be tempting to use your hand pruners to go after that large branch or leverage your loppers against the ground to get that last cut of the job. Don’t do it! If you find that you are fighting your tools to get a job, you have the wrong tool! It may not seem as serious on a small plant or branch, but it can be very dangerous for larger branches or jobs above your head!

Don’t prune when it is going to be below freezing for an extended period of time after pruning: Winter is a good time to prune, except when it is going to be below freezing for an extended period of time. This is not common in eastern North Carolina, but look at the long-range forecast before you cut! The wounds created by pruning expose the inside of the plant and can make them more susceptible to freeze damage.

Don’t prune winter- or spring-flowering plants: The best time to do a major pruning job to a plant is after it flowers. The first step to knowing when that is is to identify what the plant is and look at references to understand what you are looking for. Some plants you should not prune over the winter are: azaleas, Loropetalum, Hydrangea macrophylla or H. serrata, and deciduous Magnolias. If you see buds, try not to prune!

Do Use Best Practice

Diseased and Dying: It is always appropriate to remove diseased or dying material from plants, anytime of year. Just make sure you dispose of the material somewhere other than your compost pile and verify what the disease is, so you know whether or not it could be a long-term issue or spread to other plants.

Leave head room: It is also okay to remove branches that are impacting walkways, buildings, and neighboring plants. If you find yourself having to prune a plant every year or multiple times a year, it might be time to consider replacing it with a plant more appropriate for the space and your landscape goals.

Be patient: Treat pruning with the same respect that you would hope a doctor would have with you. Remember, you are still wounding a plant by pruning, but you are doing it in a targeted, intentional way. Just like a surgeon sowing up a patient, your cut placement will determine how quickly that plant can cover that wound and resume growth. Note: Plants don’t heal! They cover their wounds using chemicals within their tissues.

Prune plants that bloom on new wood: If we avoid pruning plants that flower on old wood in the winter, then it is true that it is okay to prune plants that flower on new wood. This is why it is okay to prune crepe myrtles (if you need to!) in the winter, because they flower on the new shoots they put out in the summer. Other things it is okay to prune in the winter: Hydrangea paniculata, grapes, roses, and Vitex spp.

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Pruning should improve the overall health and form of a plant, not be a source of trauma. Avoiding inappropriate techniques, using best practices and understanding the reasoning behind pruning can help you make the appropriate decisions for your landscape.

Amanda Wilkins is the horticulture agent for North Carolina Cooperative Extension in Lee County.