Holly trees thrive in slightly moist soil and prefer as much water as possible during the first year of planting. Watering at least once per week allows the tree to develop strong roots and thrive as it gets older. Once established, holly trees do not require additional water other than what occurs with normal rain and snow. If your area experiences a drought, begin watering at least once per week until the drought subsides.
Fertilizing for Growth
Holly trees like highly acidic soil, such as under or near pine trees. If they are planted in an area without acid soil you must fertilize it once per year to provide the necessary nutrients. There are special holly fertilizers that do the job very well and are applied either in early spring or in early fall. Slow-release granular fertilizers are best because they continue feeding the holly for longer periods of time.
Pruning for Shape
Pruning is one of the most important parts of holly tree care. In fact, though there are many holly varieties there is no distinction between a holly bush and a holly tree. A holly tree is simply a bush that was never pruned. Once the holly attains a tree form, regular pruning is required to prevent it from transforming back into a wide bushy shape.
Just as with many other trees, the proper time to prune a holly is in winter. Start by examining the trunk of the tree and look for tiny green shoots called suckers. Prune these off as close to the trunk as possible starting at the ground and going up to the lowest branch. Afterward, paint the cut edges with a liquid designed to stop tree sucker growth so that they do not grow back.
Prune the tips of each limb using pruning shears or a hedge trimmer until it has the desired shape. The only pruning rule is not to cut lower branches shorter than the upper branches, which causes the leaves to drop thus leaving the limbs permanently bare.
Winterizing for Protection
Holly trees can withstand winter temperatures well but the leaves and bark are susceptible to sunscald. To prevent this, spray a protective tree wax over the entire surface of the trunk and leaves in the early winter before temperatures drop. The wax will naturally begin to wear off in the spring. In addition, make sure to spread a 2- to 4-inch-thick layer of mulch under the tree to protect the shallow roots from freeze damage.
Holly trees are true gems in the landscape due to their beauty and hardiness. By following these steps and providing proper care for both holly trees and bushes, they will provide long lasting enjoyment in every season of the year.