How to Grow and Care for Winterberry Holly

Winterberry holly is a deciduous shrub native to the eastern United States known for its dark green leaves and bright red berries that persist through the entire winter into spring. A slow-growing shrub with a rounded upright growth habit, winterberry typically grows 3 to 15 feet tall and readily suckers and spreads to form large thickets. Winterberry holly tolerates all types of conditions except extreme dryness and grows best in wetland areas. This shrub prefers full sunlight, puts up with poorly drained acidic soil, and thrives in just about any temperature.Winterberry holly is toxic to people and animals.

Winterberry Care

Here are the main care requirements for growing winterberry holly.

• Buy a pair (male and female) of shrubs that bloom at the same time. Most quality garden centers include the gender on the plant tag so that you purchase the right pairs of plants.
• Place the malevariety within 40 to 50 feet ofa female plant for pollination and berry production. These shrubs are dioecious (with specific genders).
• Plant the shrubs in a spot with full sun for the best berry production.
• Keep soil moist and do not let the shrubs dry out. Poorly drained soil is acceptable for this shrub.

Light

Winterberry holly thrives when it is planted in a location with full sun to partial shade. To ensure ample flowering and fruiting, plant the shrub where it receives at least six to eight hours of sunlight per day.

Soil

This plant adapts to both light and heavy soils but performs best in acidic loam (pH range 5.5 to 6.5) with a good level of organic material. It does poorly in neutral to alkaline soil, which can cause fatal chlorosis (yellowing of the leaves). Feeding it with a fertilizer designed for acid-loving plants can help modify soil pH levels if a soil test reveals soil that is neutral or too alkaline.

Water

Winterberry prefers fairly wet conditions. Do not plant it in dry soil or a dry climate unless you are willing to water it frequently. This plant will require at least 1 inch of water per week, either through rainfall or irrigation.

Temperature and Humidity

Winterberry has a good tolerance for all temperature and humidity conditions across its hardiness range, though it does not do well in conditions of prolonged dryness.

Fertilizer

Winterberry holly usually doesn't require feeding unless growth is very slow. Where needed, 1/2 cup of balanced 10-10-10 fertilizer applied each spring usually is sufficient. Feeding with a fertilizer designed for acid-loving plants can help modify soil pH levels if a soil test reveals soil that is neutral or too alkaline.

Types of Winterberry Holly

Planting one of the many good cultivars of winterberry holly might be better than planting the native species because the growth characteristics of the cultivars are often preferable. Buying from a reputable local nursery can also ensure that you purchase the right male plant, which is necessary for the pollination and production of berries.

• 'Oosterwijk': This female Dutch cultivar is noted for branches that work well in floral displays, This variety grows 4 to 6 feet in height. It is pollinated by the male shrub 'Southern Gentleman'.
• 'Winter Red': This female multi-stemmed shrub produces its red berries in abundance, Mature plants grow 8 to 9 feet in height. It is pollinated by the male shrubs 'Apollo' or 'Southern Gentleman'.
• 'Cacapon': This female variety has attractive, dark, glossy green leaves and compact branching. Mature plants are 6 to 8 feet in height, with an appealing rounded growth habit. It is pollinated by the male shrubs 'Apollo', 'Jim Dandy', or 'Southern Gentleman'.
• 'Red Sprite':This female low-mounded shrub grows to a moderate 3 to 5 feet in height. Its branches remain dense right down to ground level, so it works well as a low hedge plant or in mass plantings. It is pollinated by the male shrub 'Jim Dandy'.
• 'Winter Gold': As the name implies, this female cultivar sports yellow berries that turn lighter as they age. Mature shrubs will reach 5 to 8 feet in height. It is pollinated by the male shrub 'Southern Gentleman'.
• 'Aurantiaca': This female shrub with bright pinkish-orange fruit grows 6 to 8 feet in tall. It is pollinated by the male shrub 'Jim Dandy'.
• 'Berry Poppins': This dwarf female variety grows to just 3 to 4 feet in height. It is pollinated by the male shrub 'Mr. Poppins'.

Pruning

Because the flowers (and resulting berries) appear on new growth, winterberry holly should be pruned to shape in early spring, just before new growth appears. Pruning is recommended because these shrubs not only grow tall, they also sucker profusely if not controlled. Remove up to (but no more than) 1/3 of the branches each year. Target the oldest branches, and prune them down to ground level.

Propagating Winterberry Holly

Although it's tempting to try planting seeds produced by the plentiful berries, winterberry is more effectively propagated by cutting and rooting stem cuttings, which will grow much faster than seeds. Propagating winterberry holly is best done in late spring through midsummer. Here's how:

1. Use a pair of clean sheers or pruners to trim several 2 to 3-inch stem tips from a mature female shrub that has produced berries for at least a season.
2. Remove all but the top pair of leaves on each stem.
3. Dip the cut end of the stem into rooting hormone, then insert it into a pot filled with pre-moistened standard potting soil.
4. Cover the entire pot with a plastic cover to keep humidity in and place the container in a shady outdoor location.
5. Periodically water the cuttings, ensuring the soil stays moist but not wet.
6. After a month, remove the plastic cover and continue to grow the cutting in the pot. By fall, the new plant should be ready to transplant into the garden.
   

Common Pests and Plant Diseases

Winterberry holly is generally pest- and disease-resistant. However, voles like to chew on the stems of winterberry holly in the winter. In addition, the shrub can be susceptible to leaf spots and powdery mildew, which are rarely serious. Give your shrubs more air circulation to combat leaf spots. An organic fungicide, such as neem oil, is the best treatment for powdery mildew.

How to Get Winterberry Holly to Bloom

Bloom Months

Both genders will produce flowers in late spring which will eventually turn to berries on female plants if properly pollinated.

What Do Winterberry Holly Flowers Look and Smell Like?

Small greenish-white flowers appear on female plants in spring, which, if properly pollinated by a male plant, produce a dense crop of bright red berries in the fall. The flowers may have a mild, pleasant scent.

How to Encourage More Blooms

Winterberry holly is primarily planted for its abundant and colorful berries, so it makes sense that you'd want to ensure the best show possible. A few factors directly impact how vigorously your winterberry holly will bloom, the first being the presence of compatible male and female varieties. To identify the female from the male shrubs, look at the center of their flowers: female plants will have a small green nub in the center while male plants will have pollen-bearing anthers.

Caring for Winterberry Holly After It Blooms

Regardless of gender, winterberry holly shrubs require pruning at the proper time of year to ensure a crop of berries. The plant blooms on old wood, which means the only time you should prune it is sporadically in the winter while the berries are still on the bush. But the best option is to plant the shrub somewhere where it can grow freely—that way, you don't risk pruning off future blooms and berries.

Common Problems With Winterberry Holly

Not Producing Berries

If your winterberry does not produce flowers or berries, it could be a gender issue: the right female and male pairs are not located close enough to each other. If you're still not seeing berries or flowers on your shrubs—assuming all other care requirements are met (including the proper amount of sunlight and water)—the problem could be the shrub's age. Winterberry hollies only fruit when they're well established, which can mean as many as two to three years in the ground before you'll see a display of berries.

Yellowing Leaves

If the leaves on your winterberry holly are turning yellow, the soil's pH may be higher than 6.5. This shrub does not thrive in neutral to alkaline soil.

Blotchy, Misshapen Leaves

Powdery mildew will show up on winterberry holly as white spots or blotches on leaves. The leaves can also be stunted, curled, puckered, and covered in reddish-purple blotches.

From: thespruce