Holly trees are widely recognized as a symbol of Christmas with their spiny leaves and clusters of scarlet berries. But did you know that there are over 500 species in the holly family? The American holly tree grows natively all over the eastern United States. This evergreen tree has many different varieties with native habitats all over the world. From Europe to Japan to the Caribbean.
Holly trees can add a pop of green to your winter landscape and they are excellent for borders or hedges. Some holly trees grow rather large, while there are also holly species that remain on the smaller side or dwarf size. Because these trees grow year-round they also provide cover and food sources during the winter for many birds and other wild animals. Numerous species of holly trees are dioecious, meaning that you will need to have both female and male plants for cross-pollination for the female plants to produce berries.
Many species share similar needs and management, and below we’ll discuss a generalized guide to holly tree care. Their red berries and green leaves make them stand out in the landscape, but if a gigantic holly tree isn’t your thing there are also varieties that more closely resemble small trees or rather holly bushes.
Quick Care Guide
The American holly tree (Ilex opaca) is widespread in the eastern US. Source: steveburt1947
|Height & Spread||3-25 ft wide depending on the variety and the largest varieties can grow up to 50 ft tall|
|Light||Full sun but can tolerate partial shade|
|Soil||Loamy, well-draining, slightly acidic|
|Water||2 inches of water per week|
|Pests & Diseases||Root-knot nematodes, leaf scorch, spine spot|
All About Holly Trees
Holly trees are made up of over 500 species in the Ilex family. American holly trees and European holly are the most widely recognizable holly species due to their association with Christmas Time decorations and traditions. European holly, Ilex aquifolium, is thought to have derived its name from the Latin word acrifolium, which literally translates to “sharp leaf.”
There are native species in many different climates from tropics to subtropics, but they’re most widely distributed in temperate zones worldwide. Below we’ll discuss different varieties of holly and their native ranges. Holly trees are perennial evergreens which makes them a great choice for growers in Northern climates who would like to keep some greenery around in the wintertime. Generally, the leaves are dark green with a shiny and leathery texture. They are often also very spiky, almost serrated in appearance.
Most holly species produce tiny white flowers that will bear red berries when properly pollinated. Though these are often referred to as berries, they aren’t berries at all! The red fruit is a drupe, which is more closely related to stone fruit, with a single hard seed in the center. Holly requires a low level of maintenance but will require some pruning if you wish to control its shape and growth habit.
Holly Tree Varieties
European holly (Ilex aquifolium) is what most people think of as holly. Source: nordique
American holly, Ilex opaca, has a native range in the eastern United States along the coast from Massachusetts to as far south as Florida and west to Missouri and eastern Texas. American holly grows best in USDA hardiness zones 5-9 and is cold hardy down to 20 degrees Fahrenheit. It is most easily identifiable by its bright red berries that grow in clusters at the leaf axis. Ilex opaca also has the classic spiny leaves that many hollies also possess. This native holly is a common sight in the southeastern United States.
European holly (Ilex aquifolium), also called English holly, is generally the type of holly that is depicted in Christmas decorations in much of England and North America. You may have heard the popular Christmas carol, Deck The Halls, in which you’re encouraged to bring in boughs of holly. This evergreen winterberry is also commonly used as an in-home decoration alongside mistletoe. In Celtic mythology, The Holly King is the wintertime counterpart to the summertime Oak King. Their endless battle results in the fluctuation of seasons.
Japanese holly, Ilex crenata, is more compact than American holly trees with a spread of 6-10 ft tall and wide. Because of their smaller size, they make an excellent choice for borders or hedges. These holly bushes have more of a shrub-like appearance rather than a tree and are sometimes referred to as box-leaved holly. This variety is native to Japan and other areas of southeast Asia.
Chinese holly, Ilex cornuta, is also known as horned holly which is native to China and eastern Korea. It has since been introduced to the United States and is considered to be invasive in southern states such as Kentucky, Alabama, and Mississippi. Chinese holly is considered to be the fastest-growing holly and will require regular pruning to contain its growth and shape. They are identifiable by their dark green, leathery leaves.
Dahoon holly, Ilex cassine, has a native range that begins in the southeastern states and extends into Mexico and the Caribbean. These holly bushes prefer warmer climates and do best in USDA hardiness zones 7-11. They prefer swamplands, bogs, and moist soil. This variety is diecious which means that it has separate male and female plants. The male plants will produce small white flowers that will never turn into red fruit. The female plants will bear the standard red berries.
Blue holly, Ilex meserveae, is also known as blue princess holly. This variety can be identified by its purple stems and dark blue-green foliage. This is a female hybrid that will need a male pollinator plant present to produce berries. The male varieties are known as the blue prince or blue stallion. Like most other hollies, this shrub provides year-round greenery.
Mountain holly (Ilex mucronata) has dull foliage rather than shiny. Source: Adam Balzer
Mountain holly, Ilex mucronata, also known as catberry. The foliage on this variety is dull and does not have the leathery leaves that other varieties are known for. This variety is native to the northeastern United States and as far north as Newfoundland and west into Minnesota. It is the host plant of the Columbia silkmoth caterpillars that are found in Maine. These holly plants prefer USDA zones 4-9.
Tarajo holly, Ilex latifolia, is another variety that is native to Japan and southeastern China. It has tight clusters of very tiny red berries. These trees have leaves with a pale yellow-green underside and are generally used as ornamental. The leaves can be brewed in hot water to make a tea known as bitter nail tea. This bitter tea is caffeine-free and is thought to clear the head and the eyes, for this reason, it has been used to treat the common cold.
Longstalked holly, Ilex pedunculosa, is native to China, Taiwan, and Japan. It is referred to as a lanky shrub and can be mistaken for a vine because of its tall, thin growth habit. It gets its name from the long thin peduncle, which is the stalk between the main branch and the flowers. This variety is also particularly cold-hardy.
Many of us are familiar with the yerba mate that lines the grocery store shelves, either in dried tea form or as an ingredient in canned energy drinks. But did you know that yerba mate is derived from dried holly tree leaves? Yerba mate, Ilex paraguariensis, is a variety that contains caffeine and is used to make tea in Paraguay, Uruguay, Argentina, and Brazil and has since become widely available around the world.
Yaupon is another beverage that was typically made as a traditional tribal tea amongst tribes in the southern United States. It originates from the yaupon holly, Ilex vomitoria, and is one of only two plants native to North America known to contain caffeine. Yaupon tea is gradually becoming more popular, and this holly grows throughout the southeastern United States.
Yaupon holly (Ilex vomitoria) is one of the only caffeinated US native plants. Source: kewing
Since there are so many different types of holly, we’ll discuss the general care guidelines below. Certain varieties, however, may have slightly different needs. Always consult the nursery for tips on the specific variety that you intend to purchase.
Sun and Temperature
Holly trees prefer full sun, but will also tolerate partial shade. Because the holly plant can grow very tall it’s best to plant them on the north side of your garden so they won’t be shaded out by other trees, nor will they shade out smaller plants near them. Since there are so many different varieties of holly, there is a variety for virtually every USDA growing zone. There are cold-hardy varieties that can be grown in zones 3-7 and more heat-tolerant varieties that can be grown in zones 7-above. There are types of holly that have native ranges extending into Mexico and other varieties that still have habitats as far north as Canada.
Water and Humidity
Holly trees don’t require too much in the way of water other than when they are first getting established. In the first few weeks after planting be sure to water your holly deeply at least once a week. Once the holly is established then watering can be cut back. Most hollies are quite drought-tolerant and can dry out completely between waterings. Leaving a soaker hose at the base of the tree and completely saturating the root ball is the best way to water holly during especially dry periods during the summer. These trees will not need water during the winter and will receive most of the moisture that they need from snowfall.
Hollies prefer loamy, well-draining, slightly acidic soil with a ph between 5-6. They will tolerate poorer soil quality, but you may not get flowers and therefore no berries. A soil test to determine the ph is a good idea if the berries are your goal and if the soil is too basic then it can easily be amended with a soil acidifier.
It’s best to fertilize holly trees in the mid-spring soon after the cold weather of winter has finally passed and the trees are about to begin putting on new growth. These plants love any type of slow-release fertilizer formulated for acid-loving plants. Generally, these fertilizers are formulated for blueberries and/or hydrangeas which are also acid-loving plants.
Holly trees do require pruning in their lifetime to maintain their overall shape, especially if you’re using them as a hedge. They are generally slow-growing and most only need pruning every 2-3 years. It’s best to do pruning towards the end of the growing season in August or September just before the fall/winter when the overall growth rate will slow to a stop.
Holly can be grown from seed collected from the holly berries but will take some time to reach a size that can be transplanted into the landscape. They can also be propagated from cuttings which will size up much faster. Take cuttings when doing your regular end-of-the-season pruning and dip them in rooting hormone, then place them into potting soil. Water well until roots are established. These cuttings can be grown indoors over winter and then will be ready to plant out in the spring.
Japanese holly (Ilex crenata) is a bushing holly variety. Source: Mom the Barbarian
Holly is considered to be a low-maintenance plant since it has very few pests and disease issues and is easy in terms of general care requirements. There are a few things to be on the lookout for that we’ll discuss below.
Leaf scorch can be identified by the appearance of circular tan spots that occur in early spring and summer. This can be caused by the formation of new leaves during cool and damp weather. This is sometimes out of your control due to outdoor weather conditions, however, it can be avoided by not beginning to water your holly again until mid-spring and avoiding wetting the foliage. Using a soaker hose at the base of this plant for watering will help prevent this growing problem.
Holly has little to no pests, but root knot nematodes have been known to cause issues. They tend to attack the root ball and the indicators of a nematode infestation will present as yellowing leaves, stunted growth, and dead areas of the root system. An analysis of the soil surrounding the roots will need to be done to confirm the presence of nematodes. If the plant is well cared for and healthy then generally speaking the presence of nematodes shouldn’t cause any long-term issues.
Spine spot will look like pinhead-sized spots on the leaves surrounded by a purple halo. This issue will appear in late winter after much growth has been put on during the spring and summer. It was once thought to have been caused by the spiky leaves poking themselves, but it is actually caused by ovipositing of certain insects. Ovipositing occurs when an insect deposits an egg onto the surface of the leaf. This issue is usually only cosmetic and doesn’t cause any long-term harm to your holly.
Frequently Asked Questions
Yerba mate (Ilex paraguariensis) is well-known as an energy-boosting drink. Source: Dick Culbert
Q: What is a holly tree good for?
A: Most hollies are evergreen trees that add beautiful greenery to your winter landscape. They also provide useful cover for animals and birds during winter when other plants don’t have foliage to protect them from the elements.
Q: How big does a holly tree get?
A: The largest varieties can grow to be 50 feet tall and 25-30 feet wide. However, there are also dwarf varieties and holly bushes that remain much smaller.
Q: Are holly trees or bushes?
A: Both! There are over 500 species in the Ilex family including shrubs, evergreen trees, bushes, and deciduous trees.
Q: What birds nest in holly trees?
A: Many birds are attracted to holly trees, but most commonly American Robins, Eastern Bluebirds, Hermit Thrush, and Cedar Waxwings.
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