Cultivars to Select
There are two main types of I. aquifolium that are extra appealing.
The first are the ones that produce berries in addition to the leathery, glossy leaves, while others are celebrated mainly for their variegated foliage.
If you’re a fan of the foliage and you’re okay with potentially skipping the show of berries, there’s no reason to worry about planting both male and female specimens.
Two of the cultivars I recommend here are English holly hybrids that have been bred with other species to provide better cold hardiness or a shorter stature.
There are a few cultivars of other holly species that are genuinely parthenocarpic, meaning they will produce fruit without the need for pollination, but none of them are English holly.
Here are three popular options to consider:
Argentea Marginata
A variegated English holly, this cultivar will produce scarlet berries if planted within 50 feet of a male and may possibly be pollinated by an I. opaca (aka American) male specimen.
Many choose this cultivar for the beauty of its dark-green leaves that have off-white edges. This variety grows 15 feet or taller, and spreads eight to 12 feet.
Dragon Lady
A hardy hybrid, I. x aquipernyi ‘Dragon Lady’ is a cross between I. aquifolium and I. pernyi, and this narrow variety grows 20 feet tall and spreads six feet.
A female plant, ‘Dragon Lady’ has abundant bright red berries and tough, sharp leaves recommended for property borders and defensive landscaping.
This cultivar requires no pruning to keep its formal symmetrical shape.
More cold hardy than the species plant, this holly is suited to cultivation in Zones 5 to 8.
‘Dragon Lady’ is available in one-gallon containers from Home Depot.
Royal Family Holly Combo
This is not one, but two different hybrids that have I. aquifolium as a parent plant.
The Royal Family combines a female ‘Blue Princess’ with a suitable male pollinator, ‘Blue Prince.’
Unlike traditional English holly, these two can grow in much colder climates down to Zone 4.
They’re also a bit shorter and thinner, reaching 10 to 15 feet tall and eight to 10 feet wide.
The Royal Family combo is available from Nature Hills Nursery in #1 or #3 containers.
Maintenance
Once taller than 10 feet, pruning English holly becomes fairly difficult, and must involve safety measures in addition to loppers, a ladder, and another person to spot.
Never prune a tall tree alone!
In general, unless you’re going for a specific shape, you won’t need to prune the specimens you choose to grow as trees.
But the hedges you’re trying to train as smaller 10- to 15-foot shrubs are another matter entirely.
Make sure to prune annually, in late winter, just before the plant begins growing again after its dormant period.
Use sharpened loppers, slip on some thick gardening gloves, and wear long sleeves and pants so you won’t be scratched by the spines on the leaves.
Start by cutting off any dead branches, then move to the unruly portions of branches growing sideways or towards the trunk.
Also remove any branch portions that have become tangled.
Finally, shape the rest of the shrub as needed. Mature plants can tolerate hard pruning.
Another important maintenance chore is weeding. It will help the trees to thrive if they don’t have to compete for moisture. It’s a good idea to replenish the mulch in early spring, too.
Also consider fertilizing once a year with a product designed for acid-loving trees and shrubs, like Holly Tone, available from Espoma via Amazon.
This will keep the soil at the proper pH, and encourage healthy growth.
Propagation
It’s not a good idea to try and grow I. aquifolium from seed.
The seeds take up to a year to germinate and you won’t know whether you have male or female plants for at least a couple of years after that, when they start to produce flowers.
And while seeds are widely available online, it’s impossible to tell whether you’re actually planting your desired variety until long after they sprout.
Happily, you can buy plants from nurseries and English holly is fairly simple to propagate from cuttings.
From Cuttings
The best cuttings to work with will come from the new growth.
You can either take them from dormant plants in winter or from the new wood in late spring or early summer.
Rooted cuttings are clones of the parent plants, and as such, cuttings taken from female plants will be female and those taken from male plants will be males.
Before you take your cuttings, prepare the pots. You can use three- to four-inch nursery pots, provided they have drainage holes in the bottom.
Fill your pots three-quarters full of a 50-50, pre-moistened mix of peat moss or a suitable alternative, and perlite.
Identify a branch with new growth, and cut a six- to eight-inch length of stem using clean clippers or pruners.
For each, remove the leaves from the bottom four inches of the stem. Also strip the outer bark from the bottom two inches. This creates a “wound” that will promote faster rooting.
You’ll want to use a rooting hormone, like Bontone II Rooting Powder. It’s available from Arbico Organics.
Dip the cut end that’s been stripped of leaves and bark in the powder, then jab each cutting, root powder side down, into its own prepared pot.
Cover the pots with plastic wrap or a humidity dome, and place the cuttings in a room that is 60°F or warmer, in a spot with indirect sunlight.
Keep the soil moist with a spray bottle, and you should see roots forming in four to eight weeks.
When the roots are a few inches long and are holding the plants steady, move each cutting to its own 12-inch container.
Keep them where they will receive at least six hours of indirect sunlight per day until it’s time to transplant.
Transplanting
Transplanting in winter when plants are dormant is usually best, as long as the ground is workable.
Dig a hole the same depth as the container the plant is currently growing in and about three times as wide.
Native soil should be used to fill the hole back up after the plant is seated in its new home, but you can amend this with sand or compost to improve drainage and fertility.
Ease the plant out of its growing container, being careful not to break the roots.
Use your fingers to gently loosen the feeder roots so they point down instead of tangling.
Rose Kennedy
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