​Ilex

( EYE - lecks )

At-A-Glance Information

Also called Holly, Ilex is a diverse genus of evergreen and deciduous shrubs and trees that need full sun to partial shade, regular water, and will attract birds. Take care when planting this shrub in your yard; the berries can cause upset stomach if ingested. Nearly all Ilex plants are either male or female, and both must be present for female plants to fruit. There are male-female grafted plants available that are becoming more common to avoid this fruiting setback.

Ilex Species and Varietals

The genus Ilex is the only living member of the plant family Aquifoliaceae and includes three subgenera and over 570 species. Holly growing zones vary by species; for more information see the descriptions below. To find your zone, click here: Zone Map.
Ilex aquifolium (English Holly, Common Holly, Christmas Holly)
This evergreen shrub or tree grows in zones 4-9, 14-24 and H1. This native of Southern and Central Europe and Great Britain is a slow-grower to 40 feet tall and 25 feet wide. Has many varieties that vary in leaf shape and color, and berries. Resistant to Oak Root Fungus. Varieties are outlined below.
'Gold Coast'
Gets to 6-8 feet tall, male variety. Has variegated, gold-edged leaves.
'Ferox'
(Hedgehog, Porcupine Holly)
This variety is also male, with sterile pollen. Leaves are twisted and covered in spines. 
'San Gabriel'
Has seedless berries, without pollination.
'Argentea Marginata'
Has silver-edged variegated leaves.
'Ferox Argentea'
With silver-edged variegated leaves.
'Aurea Marginata'
Gold-edged variegated leaves.
'Pinto'
Has variegated, gold-centered leaves.
'Britebush'
Gold-centered variegated leaves.
'Big Bull'
Male variety with large, nearly smooth-edged leaves.

Ilex cornuta (Chinese Holly)
Evergreen shrub or tree that grows best in zones 3-24. For this species to set fruit, it needs a long warm season. Needs protection from the sun in desert climates. Native to China and Korea, this shrub or tree can grow to 10 feet or taller and just as wide. Long-lasting berries are notably large. Those that set fruit can do so without a male present. See varieties below.
'Burfordii'
(Burford Holly)
Gets 15 feet tall and 10 feet wide. Almost spineless leaves; useful as an espalier.
'Carissa'
Dwarf variety, gets to 3-4 feet tall and 4-6 feet wide. Small leaves, good for containers. Berry-less.
'Dwarf Burford'
('Burfordii Nana')
Compact - 6 feet tall and wide. Light green, spineless leaves.
'Needlepoint'
10 feet tall and 12 feet wide. Has twisted leaves with bright red berries.
​Ilex crenata (Japanese Holly)
This evergreen shrub or tree grows in zones 4-9 and 14-24. Native to Russia, Japan, and Korea. Has a dense, erect habit and mimics Buxus in looks. Gets 4-10 feet tall and wide, and has black berries. Great for hedges, especially useful for this purpose in cold-weather regions where other hedge plants cannot be used. This species also contains some varieties that are great for topiary. See commonly grown varieties below.
'Compacta'
Rounded shrub that reaches 6 feet tall and wide, with a dense habit. 
'Convexa'
Another compact shrub, 4-6 feet tall and wide. Great for hedges. 
'Drops of Gold'
3 feet tall, 6 feet wide. Has yellow outer leaves and green inner leaves. 
'Helleri'
1 foot tall and 2 feet wide for many years after it starts growing, but can reach twice that size in about 30 years. 
'Sky Pencil'
This variety has a columnar growth habit, and reaches about 6 feet tall and just 10 inches wide. 

​Ilex 'Little Rascal'
This species grows best in zones 2b-9 and 14-22 and has a dense, rounded habit to 2 feet tall and 3 feet wide. Leaves are green and turn deep purple in winter. This is a male species.
Ilex x meserveae
Evergreen, to 10 feet tall and wide. Prefers zones 3-9 and 14-17. Most in this group are hybrids between Ilex aquifolium and a more cold-tolerant species from Japan. Hardiest of hollies. Purple stems and spiny leaves that are glossy and blue-green. Varieties are outlined below.
'Blue Girl'
Red-fruiting female variety. 
'Blue Princess'
Female variety with red fruits.
'Blue Boy'
Male variety.
'Blue Prince'
Male variety. 
'Golden Girl'
Golden berries; female plant.
'Castle Wall'
Columnar variety. 8 feet tall, 4 feet wide. Shiny, dark green leaves and red berries.

Ilex x meserveae 'China Boy' and 'China Girl'
These are hybrids between Ilex cornuta and a hardy species from Northern Japan. They are more tolerant of both heat and cold than other varieties in this species.

​Ilex glabra (Inkberry)
This evergreen shrub grows best in zones 2b-24. Native to eastern North America, this plant has spineless dark green leaves and black berries. Varieties include 'Compacta' (dwarf variety, female, 4 feet tall and wide, good hedge), 'Nordic' (dwarf variety, male, 4 feet tall and wide, good hedge), and 'Shamrock' (5 feet tall and wide, black berries).

​Ilex 'Nellie R. Stevens'
Can be a shrub or tree; evergreen. Hybrid of Ilex cornuta and Ilex aquifolium; this fast-growing plant gets to 15-20 feet tall and 10 feet wide. Leaves are glossy and green, and is self-fruiting.

​Ilex 'Red Beauty'
Evergreen shrub, zones 3b-9 and 14-24. 7-10 feet tall and 4-5 feet wide. Produces abundant crops of red berries if pollinated (a good match is Ilex x meserveae 'Blue Prince'). Foliage is dense and dark green.

​Ilex vomitoria (Yaupon)
Evergreen shrub or tree that grows best in zones 3-9, 11-24, H1 and H2. A native of the Southeastern United States, this species can take alkaline soils better than other hollies. Gets 15-20 feet tall and 10-15 feet wide. Does well with shearing, and can take on a columnar shape well. Great for topiary specimen. Scarlet berries.
'Nana' (Dwarf Yupon)
3-5 feet tall and wide. Refined and attractive; great for sheared hedge. Fruit is often hidden in leaves.
'Pendula'
Weeping habit, Male and female forms are available.
'Stokes' (Stoke's Dwarf)
3-4 feet tall and wide, Dark green leaves; male species.

Caring for and pruning Ilex shrubs

Grow Holly shrubs in well-draining soil rich in humus that is moderately fertile. These plants prefer soil with a pH of between 4.5 and 6.5 (slightly acidic). Ilex prefers being planted in full sun, especially for species or varieties with variegated foliage, or partial shade. Plant in early springtime and prune in late winter or spring each year if necessary. Each year in springtime, amend surrounding soil with compost that will serve as a slow-release fertilizer throughout the growing season by applying a thick layer over the root zone.

Propagation

Ilex can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your shrub, follow the instructions below:

Propagating Ilex by Cutting
  1. Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
  2. In winter, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch (making your cut just below a node). Because the shrub is in its dormant phase, it should have no leaves on it (unless it is an evergreen variety, in which case remove all but the top two leaves). Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
  3. Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
  4. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (or the spring afterwards if it is not growing quickly enough), when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Ilex by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
  2. Harvest your seeds. The seeds are contained inside the red (or black) fruits on the plant and will need to be removed to be planted. Either rub the seeds on a fine mesh grate or cut them open and remove the seeds, and then rinse them and set them out to dry. Once dry, the seeds can be stored in a cool, dry dark place until you are ready to work with them.
  3. Ilex seeds need to be treated before being sown. Mix together horticultural sand (50%) and peat moss (50%). Then in a separate container, mix seeds and the mixture at a ratio of 1:2 or 1:3, respectively. In a third container, place some stones (enough to cover the bottom of the container) and place the seed mixture on top. Then, fill in with more mixture until it is at the same level as the stones (it should be about 2 inches more of the mixture). Place the pot in a dry, cool, shaded area outdoors for 18 months. This allows enough time for the hard coating on the seeds to break down and allow moisture and nutrients to reach the embryo.
  4. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination can take as many as 2-3 years from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  5. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.​
Holly seeds are contained inside of the fruit produced by the shrub. Both male and female shrubs need to be present in most species to produce viable seeds.
Ilex seeds.

Problems and Pests

  • Aphids
  • Leaf Miners
  • Scale
  • Root Rot
  • Oak Root Fungus
To learn more about these issues, including how to eradicate and prevent them, consult the following links:
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Gallery

Camellias are great candidates to be grown as container plants on your patio.
Holly comes in many forms.
Ilex varieties vary in color; choose multiple colors to add depth.
Use Ilex shrubs to form topiaries.
Not all Holly leaves are spined. Some are smooth-edged.

Videos

Identifying Ilex shrubs.
All about Japanese Holly.
Looking for an alternative to Boxwood? Try Holly.
How to prune Japanese Holly.

Resources

How to Grow a Holly Tree from Seed
Propagating Holly - How to Grow Holly from Cuttings
Holly Fertilization Tips - When and How to Fertilize Holly Bushes
Wikipedia: Ilex aquifolium
Ilex crenata
Ilex
Wikipedia: Holly
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Pages 371 - 372, Ilex
If you have any questions, comments, concerns, or photos you’d like to add to the gallery, please let me know by sending me a message using the button below!
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