Whether planted as individual trees or used in hedging arrangements, the holly tree (Ilex aquifolium) is a favorite choice for landscaping needs. The glossy, evergreen leaves and vibrant, red berries make the tree stand out. There are many varieties of holly, and sizes range from 6-50 feet tall and wide. The tree thrives in areas that receive plenty of sunlight, although it does tolerate limited shady conditions. Well-drained soils are best for propagation. Fortunately, hollies tolerate various soil acidity levels.
Because holly trees don’t respond to transplanting well, you should take time to choose a wise location and time for planting, also considering where your trees will thrive best. Holly trees should be planted either in the fall or spring. Fall plantings are most beneficial in warmer climates
Before planting your holly trees, think about where they would thrive best. Remember that if you want the bright red berries, you must have both sexes nearby.
Holly trees are dioecious, meaning that there are both male and female plants. For a female plant to produce its bright berries, there must be a compatible male nearby. You can tell the difference between males and females because only the females produce berries. Also, though both sexes produce clusters of white flowers, the male's flowers have more prominent stamens. Only one male holly is needed to pollinate three or four females. Hollies of the same variety must be planted within 100 feet of each other for pollination to occur.
However, there are a few varieties that self-pollinate, such as the Foster Holly and the Burford Holly, if you do not have space for more than one holly tree.
Adequate water is necessary for your hollies in the early growing phase. Once the trees are established, you can cut back. You don’t need to water as much during the winter, however, supplemental watering is necessary during drought and as fall draws to a close before the ground freezes. Hollies cannot tolerate soggy soil, so make sure to choose a spot that is not prone to water retention.
Be sure to apply mulch during the winter after the ground freezes. Spread about 4 inches of organic mulch onto the soil around your hollies. Small wood chips or dry leaves are ideal as mulch material. This ensures that roots are well protected. You are less likely to struggle with weeds if you mulch regularly. It also helps to conserve soil moisture so that not as much will be lost through evaporation.
Remove the mulch gradually during the spring as the weather gets warmer. Re-apply in the summer to help in conserving soil moisture. Remember to keep the mulch a few inches away from the tree trunk to discourage mold and pests.
During the early growing period, it is a good idea to apply fertilizer frequently. This encourages healthy growth and supports proper root development. Give your hollies a liquid fertilizer every two weeks. Use a fertilizer designed for broad-leaved acid-loving plants such as rhododendron. Hollies react adversely to over-fertilization, so don't over-do it.
Once established, feeding hollies requires no more than one application of a slow-release granular fertilizer each year. Sprinkle fertilizer each fall onto the soil around the tree base. In lieu of commercial fertilizer, a layer of compost can be spread around the base of your tree each spring.
Prune your hollies when you notice hardening of new growth. Avoid cutting the lower branches shorter than the higher ones, as this may cause the plant to die. Maintain an even shape and remember to cut off any diseased or damaged branches. Do not prune early in the fall, as new growth may not get the chance to establish well before frost conditions manifest.
It is not always necessary to prune your hollies, but hollies can take even the extreme pruning required for formal hedges. Conduct severe pruning in the winter after berry formation. Gather all cut leaves and plant parts after pruning and get rid of them, as they can cause considerable pain if stepped on with bare feet.
Protecting Against Extreme Weather
Evergreen hollies may suffer from purple spot or sun scald during the winter because of the severe weather extremities. Foliage may also suffer from punctures caused by strong winds blowing the spiny leaves together. You can protect the leaves from the harsh winds and sun if you spray them with an anti-transpirant spray.
Installing Wind Barriers
You can also erect a wind barrier around your exposed hollies. Burlap is a good material to use for barriers. Avoid using plastic, as this will hinder healthy breathing for the plant and encourage infections and diseases to develop.
Hollies add a classic splash of color to any yard. Clusters of cheery berries and bright foliage can be snipped off and used to decorate wreaths in the winter. For an iconic look without a lot of hassle, the holly tree is always a bright addition.