by Ken Lain, the mountain gardener
Enjoy Christmas cheer all year long with this favorite holiday shrub.
Holly is most commonly associated with the Christmas season, the branches and berries a favorite component of holiday decorations. Though holly shrubs provide four-season interest, it’s during winter when they really shine. The brightly colored berries stand out against the snow, adding beauty to the winter landscape.
There’s a variety suitable for every landscape, from containers to mass plantings.
BASICS
Botanical name: Ilex x meserveae
Type: Tree to shrub
Zones: 3-10, depending on the variety
Height/Spread: Upright, mounding, spreading, columnar, pyramidal, or weeping habits, 1-1/2 to 80 feet tall and 1-1/2 to 50 feet wide
Exposure: Partial shade to full shade; berries are most prolific with the sun.
Bloom time: Spring to early summer
Flowers: Small, cup-shaped flowers bloom from spring to early summer and are most often creamy or white.
Foliage: Evergreen or deciduous foliage occurs in shades of green, blue-green, gold, or variegated. Leaves are oval or elongated, from 1/2 inch to several inches long, ranging from thick, leathery forms with spiny margins to tiny, smooth leaves that resemble boxwood.
Berries: Firm, rounded berries in shades of red, orange, yellow, pink, blue, black, or white are produced in autumn and last through winter. The fruit is a source of food for songbirds and other wildlife.
HOLLIES THAT PRODUCE BERRIES
Nearly all varieties are dioecious, with male and female flowers occurring on separate plants. This means that female plants, which produce berries, need to be sited near a male pollinator to bear fruit. One male is sufficient to pollinate 5 to 20 females and be sited within 50 feet of female plants. Plants must bloom simultaneously, so many cultivars are sold as male and female counterparts such as ‘Blue Prince’ and ‘Blue Princess.’
TOXICITY
Holly plants contain saponins, which are mild to moderately toxic if ingested. While all parts of the plants are poisonous to people and pets, it’s the attractive berries that are most often consumed.
HOW TO PLANT AND GROW HOLLY
Properly grown, Holly makes a beautiful Shrub and fantastic for topiaries. The secret to growing healthy Holly is to provide cool nights with bright days.
LIGHT
In both winter and summer, Holly requires bright light but avoid direct sunlight in summer. In winter, plants can accept a bit of direct sunlight, such as south-facing windows.
SOIL
Fertile, moist, well-drained soil is ideal for Holly. In dryer mountain soils, the ground should be heavily mulched to retain moisture and keep it cool. In containers, Holly grows best in Watters Organic Potting Soil.
Water newly planted trees regularly with a garden hose for at least one month (2 months in Summer). Automatic irrigation systems may not be sufficient initially. Water frequency will vary according to the season, exposure, and plant size.
April – Oct this Holly should be irrigated 2 x weekly.
Nov – Mar this Holly should be irrigated 2 x monthly.
Potted Holly prefers moist, humid conditions, but not soaking. Don’t let the soil dry out, and keep it evenly moist.
TEMPERATURE AND HUMIDITY
Outdoors, Holly does best in moderate conditions, protected from both harsh winter winds and excessive summer heat. Very humid conditions can encourage root rot and bacterial leaf spot.
Feed 4x Times per Year with either 7-4-4 All Purpose Plant Food, Soil Sulfur, or Humic. Here’s the recommendation by season:
Spring = 7-4-4 All Purpose Food + Soil Sulfur
Summer = 7-4-4 All Purpose Food + Humic
September = 7-4-4 All Purpose Food
December = 7-4-4 All Purpose Food
REPOTTING
Repot small holly plants into fresh Watters Potting Soil every year, or every other year for larger plants. Old, tired plants can be refreshed and replanted into their same containers with new Potting soil.
PRUNING
Hollies look best when allowed to retain their natural shape and size. Some types lend themselves to shearing into formal hedging. It’s hard to make a mistake when pruning Holly. It grows with such vigor you simply feed with Watters 7-4-4 Plant Food, and the shrub will grow its way out of any error. To keep Holly compact and bushy, pinch off the growing tips.
COMMON PESTS/ DISEASES
Aphids and spider mites are the most common pests. Spray with Watters Multi-Purpose Insect Control for the best treatment.
The most severe diseases include Xanthomonas (bacterial leaf spot) and Rhizoctonia root rot. Bacterial leaf spot is identified by brown or black spots on the leaves. Severe cases cause stems to become twisted and distorted. Affected plants should be removed and destroyed, and remaining plants can be sprayed with Copper Fungicide. Discard diseased plants and treat remaining plants with a Revitalize fungicide.
Deer resistance:
Holly is often listed as deer resistant, but some are more resistant than others. Those with spiny leaves tend to be left alone. Winterberry and inkberry are also less bothered, while blue Holly and Japanese Holly are more susceptible to grazing. See more deer-resistant plants.
HOLLY LANDSCAPING TIPS
There are many ways to incorporate Holly into your landscape. Here’s how:
- Combine a small or medium-sized evergreen type with other evergreen shrubs along the front of your home. Decorate the shrubs with holiday lights for the whole neighborhood to enjoy.
- Place a colorful ceramic container near your home’s entryway and plant with a smaller specimen. Add decorations and little twinkling lights for a festive look.
- Plant a dwarf type as a hedge along a pathway and keep it sheared to create formal structure in transition areas.
- Naturalize evergreen or deciduous forms with especially showy berries in a woodland border that can be enjoyed from a cozy window inside your home. Add other plants with winter interest, such as witch hazel and hellebores, for an inspiring view that will help stave off the winter blues.
- Mass a dwarf or groundcover type along a bank or slope for erosion control.
- If you regularly use the berries and branches for holiday decorating, make sure that plants are easily accessible for harvesting. Choose a site close to your home or driveway that won’t be blocked by snow.
HOLLY VARIETIES
‘Blue Princess’, Blue Holly
Ilex x meserveae
Zone: 5-9
Height/Spread: Upright, bushy habit, 8-15 feet tall, 6-10 feet wide.
Color: Dark blue-green foliage, purple stems, white flowers, red berries
Showy red fruits stand out against spiny, blue-green foliage. It can be left to grow naturally or sheared into formal shapes. Sheared plants will produce fewer berries. Grow this evergreen along a slope, as hedging, or in a foundation planting. Has an abundance of fruit when sited near a male pollinator such as ‘Blue Prince.’
Berry Poppins, Winterberry
Zone: 3-9
Height/Spread: Upright vase-shaped habit, 3-4 feet tall and wide
Color: White flowers, green foliage, red berries
This dwarf deciduous shrub produces lots of bright red berries that hold on through the winter. Combine with a male pollinator such as Mr. Poppins® winterberry to set fruit. The right choice for small urban yards. Use as a foundation planting, massed along a slope, as hedging or screening.
Gem Box, Inkberry Holly
Ilex glabra
Zone: 5-9
Height/Spread: Compact rounded habit, 2-3 feet tall and wide
Color: Dark green leaves, red-tipped new growth, white flowers, black berries.
A boxwood look-alike is suitable for hedging. Grown primarily for the foliage, the berries are inconspicuous and need a male plant to produce fruit. Use this dwarf evergreen as edging along a pathway or garden room, in mass plantings, or as a container accent.
Brass Buckle, Japanese Holly
Ilex crenata
Zone: 6-8
Height/Spread: Dwarf compact habit, 12-18 inches tall and wide
Color: Golden foliage with green undertones, white flowers
One of the smallest hollies, this evergreen shrub is grown for its attractive gold foliage. Use in patio containers, as edging, in borders, mass plantings, or rock gardens. Foliage is burn-resistant.
Sky Box, Japanese Holly
Ilex crenata
Zone: 6-8
Height/Spread: Upright columnar habit, 4-5 feet tall, 2-3 feet wide
Color: Dark green foliage, white flowers
Formerly grown as Sky Pointer and can be developed as an alternative to upright forms of boxwood. The shiny dark evergreen foliage and narrow columnar habit add unique year-round interest. Maintains its columnar structure with little or no pruning.
Little Goblin Red, Winterberry
Ilex verticillata
Zone: 3-9
Height/Spread: Upright dwarf habit, 3 to 5 feet tall and wide
Color: Green foliage, white flowers, red berries
Tolerant of wet conditions, this dwarf deciduous shrub may be planted in a bog or rain garden. A site near a male pollinator such as Little Goblin Guy for berries. Suitable for small urban yards, mass plantings, containers, and hedging.
Berry Heavy Gold, Winterberry
Ilex verticillata
Zone: 3-9
Height/Spread: Upright, bushy habit, 6 to 8 feet tall and wide
Color: Green foliage, white flowers, yellow berries
One of the best gold varieties, named for its abundance of large bright yellow berries, pairs well with orange or red varieties. Combine with a male pollinator such as Mr. Poppins. Grow this medium-sized deciduous shrub as hedging, screening, or in a woodland setting.
Castle Spire, Blue Holly
Ilex x meserveae
Zone: 5-7
Height/Spread: Upright tapered habit, 6-10 feet tall, 3-4 feet wide
Color: Dark blue-green foliage, white flowers, red berries
Evergreen shrub with thick glossy leaves with spiny edges. The narrow pyramidal shape, dark foliage, and red berries look incredibly picturesque in fresh snow. Can be lightly sheared into Christmas tree form. Grow as hedging, screening, use as a foundation plant, or landscape accent. Plant near a male pollinator such as Castle Wall to set fruit.
‘Nana’, Yaupon Holly
Ilex vomitoria
Zone: 7-10
Height/Spread: Mounding spreading habit, 2 to 5 feet tall and 3-5 feet wide.
Color: Green foliage, white flowers, red berries
Grown primarily for finely textured leaves similar to boxwood, this dwarf variety tolerates pruning and shearing. A right choice as formal hedging, ground cover along a slope, or screening between garden rooms. Needs a male pollinator to bear fruit.
Blue Princess Holly
Ilex x meserveae
Zone: 5-9
Height/Spread: Upright, bushy habit, 8-15 feet tall, 6-10 feet wide.
Color: Dark blue-green foliage, purple stems, white flowers, red berries
Showy red fruits stand out against spiny, blue-green foliage. It can be left to grow naturally or sheared into formal shapes. Sheared plants will produce fewer berries. Grow this evergreen along a slope, as hedging, or in a foundation planting. Has an abundance of fruit when sited near a male pollinator such as ‘Blue Prince.’
Berry Poppins, Winterberry
Ilex verticillata
Zone: 3-9
Height/Spread: Upright vase-shaped habit, 3-4 feet tall and wide
Color White flowers, green foliage, red berries
This dwarf deciduous shrub produces lots of bright red berries that hold on through the winter. Combine with a male pollinator such as Mr. Poppins winterberry to set fruit. The right choice for small urban yards. Use as a foundation planting, massed along a slope, as hedging or screening.
Gem Box, Inkberry Holly
Ilex glabra
Zone: 5-9
Height/Spread: Compact rounded habit, 2-3 feet tall and wide
Color: Dark green leaves, red-tipped new growth, white flowers, black berries
A boxwood look-alike suitable for hedging. Grown primarily for the foliage, the berries are inconspicuous and need a male plant to produce fruit. Use this dwarf evergreen as edging along a pathway or garden room, in mass plantings, or as a container accent.
Brass Buckle, Japanese Holly
Ilex crenata
Zone 6-8
Height/Spread: Dwarf compact habit, 12-18 inches tall and wide
Color: Golden foliage with green undertones, white flowers
One of the smallest hollies, this evergreen shrub is grown for its attractive gold foliage. Use in patio containers, as edging, in borders, mass plantings, or rock gardens. Foliage is burn-resistant.
Sky Box, Japanese Holly
Zone: 6-8
Height/Spread: Upright columnar habit, 4-5 feet tall, 2-3 feet wide
Color: Dark green foliage, white flowers
Formerly grown as Sky Pointer and can be developed as an alternative to upright forms of boxwood. The shiny dark evergreen foliage and narrow columnar habit add unique year-round interest. Mass in a row as hedging or screening or use as a container accent. Maintains its columnar structure with little or no pruning.
Little Goblin Red, Winterberry
Ilex verticillata
Zone: 3-9
Height/Spread: Upright dwarf habit, 3 to 5 feet tall and wide
Color: Green foliage, white flowers, red berries
Tolerant of wet conditions, this dwarf deciduous shrub may be planted in a bog or rain garden. Plant near a male pollinator such as Little Goblin Guy for berries. Suitable for small urban yards, mass plantings, containers, and hedging.
Berry Heavy Gold, Winterberry
Zone: 3-9
Height/Spread: Upright, bushy habit, 6 to 8 feet tall and wide
Color: Green foliage, white flowers, yellow berries
One of the best gold varieties, named for its abundance of large bright yellow berries, pairs well with orange or red varieties. Combine with a male pollinator such as Mr. Poppins. Grow this medium-sized deciduous shrub as hedging, screening, or in a woodland setting.
Castle Spire, Blue Holly
Ilex x meserveae
Zone: 5-7
Height/Spread: Upright tapered habit, 6-10 feet tall, 3-4 feet wide
Color: Dark blue-green foliage, white flowers, red berries
Evergreen shrub with thick glossy leaves with spiny edges. The narrow pyramidal shape, dark foliage, and red berries look incredibly picturesque in fresh snow. Can be lightly sheared into Christmas tree form. Grow as hedging, screening, use as a foundation plant, or landscape accent. Plant near a male pollinator such as Castle Wall to set fruit.
‘Nana’, Yaupon Holly
Ilex vomitoria
Zone: 7-10
Height/Spread: Mounding spreading habit, 2 to 5 feet tall and 3-5 feet wide.
Color: Green foliage, white flowers, red berries
Grown primarily for finely textured leaves similar to boxwood, this dwarf variety tolerates pruning and shearing. A right choice as formal hedging, ground cover along a slope, or screening between garden rooms. Needs a male pollinator to bear fruit.
‘Blue Princess’, Blue Holly
Ilex x meserveae
Zone: 5-9
Height/Spread: Upright, bushy habit, 8-15 feet tall, 6-10 feet wide.
Color: Dark blue-green foliage, purple stems, white flowers, red berries
Showy red fruits stand out against spiny, blue-green foliage. It can be left to grow naturally or sheared into formal shapes. Sheared plants will produce fewer berries. Grow this evergreen along a slope, as hedging, or in a foundation planting. Has an abundance of fruit when sited near a male pollinator such as ‘Blue Prince.’