Shearing is the act of maintenance where you simply trim the outermost twigs to control length. Thinning is where you cut and remove branches throughout the shrub. Thinning is generally preferred over shearing, as exclusively shearing will encourage dense growth on the outer edges of the plant and keep sunlight from getting to inner branches. This can create a transparent or hollow look which is considered less desirable than a full, even growth. [3] X Trustworthy Source University of Georgia Cooperative Extension Division of the University of Georgia focused on research and community education Go to source A terminal bud grows at the tip of a branch, and it sends hormones back down the rest of the shoot which inhibit the growth of other buds. This is why you want to prune: you want to clip off terminal buds in order to stem the flow of growth-inhibiting hormones and encourage growth of other, non-terminal buds. [4] X Research source A lateral bud sprout along the side of the shoot. When cutting, you want to cut back to a lateral bud node, which is the place on the stem where the lateral bud attaches to the shoot. [5] X Research source
If your holly plant loses its foliage every winter, it’s a deciduous holly. These holly plants require radical pruning every year. If your holly plant never loses its foliage, it’s an evergreen. These types of holly require more attention in the first few years of life but not as much thinning or shaping as time goes on.
For rounded hollies, you should thin during the first few years and do formal shaping throughout its life. Pyramidal hollies require similar thinning regimens but little if any formal shaping throughout life. Indeterminate hollies need both throughout life. [7] X Research source
Pruning shears work well on twigs and branches measuring 1/2 inch (1. 3 cm) in diameter or less. A quality pair of lopping shears can cut branches measuring up to 2 inches (5 cm). Make sure to use ratchet-style pruners and avoid anvil-style. Larger limbs and branches may require the use of a pruning saw.
The best time to prune a deciduous holly is in spring as it produces optimal berry growth. For evergreen hollies, prune in the dead of winter when they’re dormant – try pruning in December and using the branches as a holiday decor. [9] X Research source Tend to holly shrubs that are diseased or have broken wood as soon as you recognize that the shrub has health issues.
If you disregard this principle and leave stubs from the places where you’ve cut, the stubs will heal more slowly. It also leaves the plant more susceptible to insects and diseases.
Pruning intersecting branches at their union will help you create a more organized framework of branches. This gives the shrub a nice, natural shape which needs minimal pruning later. [12] X Research source
In addition to rubbing alcohol, you can also use a solution made from pine oil cleaner, household bleach, or ammonium salts. Soak your tools in the solution for at least five minutes, and then rinse with water. [14] X Research source
Shear along the surface of leaf growth to make sure the cut is even. Perform regular trimming by cutting the outermost twigs to the nearest bud node. [15] X Research source If your holly shrubs do not function as hedges or formal decorative pieces, allow them to grow naturally.
Open up the shrub with thinning cuts if you have disease issues, in order to promote air circulation. Several different types of root rot affect holly shrubs, so look out for yellow spots on the leaves, dark black roots, and stunting as common symptoms of these problems.
The most common signs of infestation are discoloration, trails, or speckling on the foliage.
