Awash with a riot of color in early spring, a loropetalum or fringe flower shrub (Loropetalum chinense) holds the promise of warm weather that's just around the corner. Fringe flower, which produces fringy petals, grows in U.S. Department of Agriculture plant hardiness zones 7 through 9. The flowers may be hot pink, shades of red or pure white, depending on the cultivar. Prune fringe flower at the right time of year so you don't stop its showy, colorful display before it even gets started.
When fringe flower blooms in early spring, those flower buds started forming on the previous year's stems -- called old wood or old growth. To avoid cutting off these flower buds, prune fringe flower soon after it finishes flowering in spring. This gives the plant time to produce new stem growth where flower buds begin forming for next year's display.
If you wait until the fall to prune fringe flower, you will remove the flower buds for the following spring's blossoms and you may encourage the shrub to produce tender new leaves that are susceptible to frost damage.
Fringe flower is a multistemmed shrub whose natural shape is typically upright -- having an overall rounded appearance with slightly arching stems. Some cultivars with medium heights, such as 'Ruby' Chinese fringe flower (Loropetalum chinense 'Ruby,' USDA zones 7 through 9) that tops out at only 5 feet tall, may need only a little nip and tuck to keep them in bounds. There are no hard-and-fast rules about how much to prune or where to make pruning cuts when shaping a fringe flower shrub, so be guided by what looks best to you.
One notable exception to upright loropetalum cultivars is Purple Pixie fringe flower (Loropetalum chinense var. rubrum 'Shang-Lo,' also called 'Peack,' USDA zones 7 through 10). Purple Pixie grows only 1 to 2 feet tall, but it has a 4- to 5-foot spread, which makes it suitable as a ground cover or a cascading container plant. You may choose not to prune this cultivar, letting it keep its natural form.
Prune tall cultivars with a technique called "limbing up" to give them a tree form. 'Zhuzhou Fuchsia' fringe flower (Loropetalum chinense 'Zhuzhou Fuchsia,' USDA zones 7 through 9) may grow 20 feet tall, which is the height of small trees. Remove the lower branches -- to the height you want -- by cutting the horizontal branches back to the main vertical stems.
Fringe flower is typically disease-free, but it may succumb to a disease called bacterial gall, which is caused by the pathogen Pseudomonas savastanoi. The bacteria infect fringe flower shrubs by entering through pruning wounds or hail-damaged stems or branches. The disease causes knotty galls to form on the shrub's stems. Prune branches several inches below the galls, back to healthy parts of the shrub, and discard the diseased branches.
Before pruning fringe flower shrubs, particularly when cutting diseased branches, disinfect your pruning tools. Soak the blades in a solution of 1 part household pine oil cleaner and 3 parts water. Rinse the blades with water, or allow them to air-dry before cutting plants. If you're pruning to remove bacterial galls, disinfect the pruners between each cut.
Choose pruning tools based on the size of the branches you need to cut:
- Handheld pruning shears work for small twigs or branches -- up to 1/2 inch in diameter -- just to tidy up a fringe flower shrub. Choose bypass or anvil hand pruners.
- Long-handled lopping shears work for branches that are 1/2 inch to 1 1/2 inches in diameter. Long-handled lopping shears give the leverage to make cutting easier.
- Use pruning saws if the branches you need to cut are larger than 1 1/2 inches in diameter. This is not the same as a carpenter's saw -- it has a narrower blade that's easier to maneuver inside the shrub.
- Pole pruners come in handy for tall cultivars that you cannot reach from the ground. Although the cutting mechanism is overhead, you operate it by pulling downward on a rope that's attached to the blade.
Be careful when using any sharp cutting tools. Wear gloves to protect your hands, and wear head and eye protection if you're cutting overhead. Be careful of falling branches.