Pruning Spring-blooming Shrubs in Your Landscape

Now that spring has sprung and we’ve enjoyed our early bloomers, it’s time to take care of a few maintenance tasks in the garden. Shrubs like forsythia, early azaleas, and dogwood all bloom early in the spring. It’s time to prune them after they bloom and before they set buds for next year. A few of them, like oakleaf hydrangea and the later-blooming azaleas, may not yet have bloomed, so be sure to wait until these plants have bloomed before you prune. Don’t delay, though. If you delay pruning these plants too long, like into the summer, you will likely remove next year’s flower buds.

Gather your tools. To cut branches about the diameter of a pencil, hand shears will suffice. Loppers have longer handles, giving you more leverage to cut through larger branches, up to about half an inch in diameter. If you need to cut through branches larger than that, be sure to gather a pruning saw. A pruning saw has a narrower blade (for easier maneuvering) and coarser points or teeth than a common carpentry saw. Most pruning saws also have curved blades that cut on the draw stroke (pulling the blade toward you). A wheelbarrow or garden pushcart will be helpful when gathering the clippings as you prune. You can also lay a tarp on the ground near your work space and gather branches and limbs there. You may also opt to grab hedge shears to create a neatly trimmed appearance, but this may not be the best tool for the job. We’ll explore that more below.

Before you start pruning, think first about what you want to achieve with pruning. This will determine how you approach the task. Do you simply want to trim and neaten the plant, or do you need to reduce the plant height? Does the plant need invigoration? The answers to these questions will determine how much you remove from the plant. Remember, though, that pruning actually encourages growth, so it’s important to prune with a purpose.

• Trim and neaten. For plants that are well suited for their space, are not overgrown or growing too vigorously, or are even pruned regularly, a simple “nip and tuck” may be all that is needed. Using a pair of hand shears or loppers to remove any wayward branches will quickly tidy the plant’s appearance. Azaleas often benefit rom this type of maintenance. They tend to send up longer branches with leaves and flowers at the top. If you shear the plant with a pair of hedge trimmers, you’ll leave stubs that will form proliferations of growth and will detract from next spring’s blooms. Instead, select the stem that you want to shorten, follow it with your hand down into the plant, and prune above where it emerges from another plant stem.
• Reduce plant height. Some shrubs will need to be shortened so that you can clear a site line at a driveway or remove growth covering a window. Plan to remove as much as one-third of the plant height this season. Use loppers to prune larger branches within the plant canopy. Choose limbs strategically, using a process known as thinning. Cut selected branches back to a lateral branch, a lateral bud or the main trunk. Thinning encourages new growth within interior portions of a shrub, reduces size, and gives a fuller, more attractive plant. You may need the hand pruners to tidy the shrub’s shape after pruning.
• Invigoration. If you decide that your plant needs renewed growth and overall better shape, renewal pruning may be an option saved for next year. The best time to prune severely is when spring growth begins — mid-March in north Georgia and mid-February in South Georgia. This drastic approach reduces plants to 6 to 12” in height, leaving your landscape looking less attractive until plants regrow. Pruning saws will be needed to handle branches that are larger in diameter. In time, many plants will regrow from this reduced state, but some, like boxwood and junipers, will often die. If you have a shrub that is simply too large for the space in which it is planted, a better management decision is to remove it and replant with something that requires less pruning and maintenance.

When you are pruning your spring-flowering shrubs, resist the urge to shear them. This technique is often achieved with hedge trimmers, either manual, electric, or gas-powered. Hedge trimmers make many simultaneous cuts across the top of the shrub, a technique referred to as “heading.” The plant responds with regrowth very near to where these cuts are made., resulting in dense regrowth on the outer shell of the plant. Repeated heading cuts result in increased problems with insects and disease as well as a structural weakening of the plant. With all the concentrated growth at the tips of the plant, the interior begins to look very bare. The plant then becomes vulnerable to wind, ice, or other storm damage. Instead of making shearing or heading cuts, use thinning cuts. This will ensure that the plant continues to produce internal growth, resulting in a healthy structure and a full appearance.

Plants to Prune After Flowering

For additional pruning explanations and techniques, be sure to read UGA Extension publications B961 Pruning Ornamental Plants in the Landscape found on the UGA Extension publication website.

Picture Caption: Repeated heading cuts with hedge clippers result in an outer layer of growth but no active buds on the plant’s interior.

Picture Caption: Azaleas are pruned in the spring after they have finished flowering. To reduce height and neaten the shrub’s shape, follow the branches into the plant and remove where they connect to the main plant.