How to Plant and Grow Holly

Holly's big plant family includes hundreds of varieties ranging from 50-foot-tall trees to petite shrubs that stand only a few feet tall. Nearly all variations can be sorted into four basic groups: English holly (glossy, spiny foliage); American holly (similar to its English cousin, but with duller leaves); Chinese holly (large glossy, spineless varieties); and hybrid holly. In other words, there is probably a holly in this diverse plant group that suits your landscape.

Many holly plants will produce colorful fruit that remains in place for three to six months of the year, depending on the density of the wildlife population. Whether you want to showcase these colorful berries in the yard or use them to perk up floral arrangements and holiday displays, you need to have separate male and female plants near each other in the landscape.

The berries of the Ilex genus of plants (including American holly and English holly) are generally considered toxic to humans and pets.

Where to Plant Holly

Most hollies like full sun to partial shade. They can tolerate many soil types but thrive best in loamy, well-draining soil with a slightly acidic pH (5.0 to 6.0). If grown in more alkaline-based soils, holly foliage may turn yellow, and the shrub may struggle.  

Holly provides year-round interest while serving as part of a hedge or perennial border, or in foundation plantings. Evergreen varieties take center stage in winter when they anchor leafless garden beds. Tall evergreen hollies are good for creating a dense hedge or screen. When used as barrier plants, holly varieties with spiny leaves are nearly impenetrable. No matter where you plant holly, if pollinated, its colorful berries add splashes of winter color and food for birds.

How and When to Plant Holly

The best time to add holly plants to your yard is in the milder months of spring or fall. To plant a new shrub, dig a hole approximately two or three times the size of the plant’s root ball, but not quite as deep. You will want the top of the root ball level with or slightly above the soil line. Place the plant and fill the hole with soil. As you work, wet the soil, and tamp it down to remove air pockets. Add a 2 to 3-inch layer of organic mulch over the roots to help the soil retain even moisture.

If you are planting multiple holly plants, allow about 5 feet of space between plants for small varieties, or if you plan to grow a hedge. For larger tree-like holly plants, allow as much as 25 feet of space between plants.  

Male vs. Female Holly

Most types of holly are either male or female—and female plants depend upon male pollination to produce berries. Check plant tags carefully when purchasing holly to ensure you buy at least one male plant to pollinate 10 to 20 female cultivars. Choosing a male and female of the same variety helps ensure the plants bloom simultaneously—a key factor if you expect bees and other pollinators to work their magic.

If you don’t have labels to rely on, look at the flowers that appear in spring. Male holly flowers have more prominent stamens than female flowers. The female holly flowers feature a swollen base or bump that contains the eggs. Once pollinated, these bumps will become berries. If you see a holly
plant with berries, it is most likely a female.

Holly Care Tips

Once planted and established, holly is a fairly low-maintenance shrub. They are slow-growing and don’t need much (if any) pruning but may require some attention to conserve and maintain soil moisture levels.

Light

Read plant tags carefully when selecting a planting site for holly. Some hollies prefer full sun, while other varieties prefer partial shade. If uncertain, choose an area with at least 4 to 6 hours of direct sunlight each day. In very hot climates, look for areas with shade from the harsh afternoon sun.

Soil and Water

Most hollies prefer loamy, well-draining, acidic soil with a pH of 5.0 to 6.0, but some (like Winterberry) can survive in boggy soils.

Holly bushes need consistently moist—but not waterlogged—soil when acclimating for the first year. After the first year, they are more drought tolerant but will still thrive best with moderately moist soil. Natural rainfall may be enough but if rainfall in your region averages less than 1 inch per week, you may need supplemental watering to keep your holly foliage bright and healthy. You can also add a few inches of mulch around the base (but not touching the trunk) to help the soil retain its moisture.

Temperature and Humidity

Like the light requirements, temperature and humidity tolerances vary throughout the Ilex genus. American holly, for example, is hardy in zones 5 through 9, so it can tolerate temperatures as low as -20 degrees Fahrenheit—especially if it is sheltered from drying winter winds. In the hottest temperatures of the warmest climates, your American holly foliage may droop but recover. English holly (which is hardy in Zones 6-9) is slightly less tolerant of extreme hot and cold temperatures. Deep, prolonged frosts may damage or kill the plants, and extreme heat without shelter may cause the leaves to droop and scorch.

Fertilizer

Fertilize in spring and fall with a fertilizer designed for evergreen or acid-loving plants to keep your holly plants at their best. For the amount to use, consult the product label directions.

Pruning

Holly shrubs don't typically require pruning unless they become unwieldy or you want to create a hedge or geometric shape. Late spring is a good time to tackle this task. On the question of whether or not (and when) to prune, the holly family is so diverse that it's impossible to give one answer that will work for all varieties. In general, wait until dormancy for most hollies.

Pruning in late fall or early winter means you can use the clippings in holiday arrangements or wreaths. On the other hand, if you prune in late winter, you can enjoy seeing the berries outside when most plants are bare. There is no single right answer. Just don't prune in late summer or the plant might put out new growth that will die when frosts arrive.

Pests and Problems

Holly plants are mostly deer-resistant, but you may have to keep an eye out for aphids, leafminers, spider mites, whitefly, and scale.

Holly plants are also prone to issues with fungal rot, tar spot, and cankers. Many of these problems can be prevented by avoiding overwatering, removing debris from the base of the plant, pruning away overcrowded growth, and making sure your plant has good air circulation.

How to Propagate Holly

The best way to propagate holly is via hardwood cuttings that are taken in late spring or early summer. Holly seeds are typically too low in viability to be a reliable source for propagation.

Wearing gloves, select a 4-to-6-inch branch with both soft, immature leaves at the tip and sturdy mature leaves at the base. Cut it just below a bud union with sharp pruning shears. Use your shears to remove all of the mature leaves and some of the bark from the base of the cutting. Dip the cut end of the prepared cutting in a rooting hormone powder and poke the cutting into a grow pot prepared with a moist rooting medium. Secure the stem by tamping the soil down. Wrap your grow pot in a plastic bag and place your cutting in a sheltered area that receives dappled sunshine and keep it at an ambient temperature of 75 to 80 degrees Fahrenheit. Mist the foliage daily and keep the soil evenly moist, but not saturated. It will likely take 2 to 3 months for your cutting to take root, but once it does, you can remove the plastic bag. Keep it in a spot with bright, indirect light to continue growing. In the following spring (or when the soil temperatures are consistently above 50 degrees), you can transplant your sapling to a spot in your garden.

Types of Holly

The diverse holly family includes trees and shrubs that come in a variety of forms: columnar, pyramidal, rounded, or weeping. Their foliage varies, too, ranging from large, spiny leaves to smooth, small leaves that resemble boxwood. Even holly's berries come in a variety of hues that include red, pink, blue, orange, yellow, and white.

'Blue Boy' Holly

Ilex x meservae 'Blue Boy' has deeply-hued foliage and stems. It's extra hardy. Plant this hybrid variety next to female hollies as a pollenizer. It grows 6 to 8 feet tall and 3 to 6 feet wide.

Zones: 5–9

'Blue Girl' Holly

This variety is an exceptionally hardy hybrid holly with dense blue-green foliage and bright red berries from fall through winter. Plant 'Blue Boy' nearby as a pollenizer.

Zones: 5–9

'Jersey Delight' Holly

Ilex opaca 'Jersey Delight' is a female variety with bright red fruits. Plant with 'Jersey Knight' for fruit set. It grows 50 feet tall and 40 feet wide.

Zones: 5–9

Winterberry

Ilex verticillata is a hardy, deciduous holly strung with big crops of bright red berries on winter-bare branches. It grows to approximately 8 feet tall and wide. Unlike most hollies that prefer loamy soil, winterberry also tolerates boggy soil. 

Zones: 3–9

'Winter Gold' Holly

This selection of lex verticillata shows off clusters of golden-yellow berries in late fall. The plant tolerates a wide variety of soils, though it does best in moist, well-drained ground. It can grow 8 feet tall and 10 feet wide.

Zones 4–9

Yaupon Holly

Ilex vomitoria is native to North America and grows 15 feet tall and 10 feet wide. It tolerates wet soil well and is a top hedge variety.

Zones: 8–10

Companion Plants for Holly

Since holly plants start small and slowly grow much larger, consider annual plantings (instead of perennials) that can be adjusted as your holly changes shape and size. Or, if your holly shrub is already large, choose plants that are okay living in its shadow.

Periwinkle

If you want to add a blanket of flowers around the base of your holly plant, look no further than the shade-loving periwinkle. It has a vigorous sprawling habit and can easily colonize any area, so keep volunteer plants in check to prevent them from becoming invasive. If you do, you will be rewarded with a sea of cheerful blue or purple blooms. Periwinkle is hardy in Zones 4-9.

Lobelia

Annual lobelia brings pretty blooms to the cool weather of spring and fall. Except for cool-summer areas, it may stop blooming during the heat of summer, but you can sheer it back for an encore bloom in the fall. Lobelia is hardy in Zones 2-11.

Cotoneaster

Cotoneaster would make a great low-growing shrub to add around tall holly shrubs. In the spring, it is covered in small blossoms of white and pink followed by bright fall berries. It prefers well-draining soil and is hardy in Zones 4-7.

Juniper

If you are looking for a larger companion plant or shrub, you can’t go wrong with a sturdy evergreen like Juniper. It prefers similarly acidic soil and can even provide your holly with shelter from harsh winds and sunlight.  Juniper trees are hardy in Zones 3-9

Hosta

If you are looking for a low-maintenance plant that will thrive under a tall holly shrub, a blue-leaf hosta might be a good choice. They also like moist, loamy soils and won’t mind the shade your holly shrub provides. Blue leaf hostas prefer dappled to full shade and are hardy in Zones 3-9.