English holly (Ilex aquifolium) is a broadleaf evergreen tree/shrub that can grow from five to 18 metres high. Reddish orange berries are found on female trees.
English holly is native to the British Isles and southern and central Europe. Grown ornamentally in North America, it has escaped into forested areas where it grows in shade or sun in well-drained soil. It can grow from seed (in berries) and vegetatively. Ilex aquifolium can form dense thickets that dominate the tall shrub layer in the forest and suppress germination and growth of native tree and shrub species on the forest floor. It is also a notorious water hog, thus preventing native plants from obtaining sufficient water and the nutrients contained within it.
Small plants can be pulled or dug up when soil is moist. Mature trees have deep and extensive roots so digging is labor-intensive and results in considerable soil disturbance if all of the roots are removed. Cutting holly at the base usually results in re-sprouting from the crown, but with monitoring and follow up this can suppress the holly. Applying herbicide with the cut stump or frilling method are most effective. Foliar herbicide treatment is not very effective due to the thick, waxy leaves. Alternative for planting include:
- Oregon grape (Mahonia nervosa)
- tall Oregon grape (Mahonia aquifolium)
- Pacific crabapple (Malus fusca)
- arbutus (Arbutus menziesii)
All native species to BC and will provide habitat for native wildlife.
- Large, dense, slow-growing, evergreen tree or shrub, 15 to 50 feet tall and up to 15 feet wide or more
- Can grow as either a single-trunked tree or a multi-stemmed thicket
- Leaves are thick, glossy, dark green and wavy, 1-3 inches long, alternate and simple
- Leaves usually have sharp, stout spines along edges although may be smooth on older branches
- Flowers are small, whitish, inconspicuous, sweetly scented
- Bunches of red, yellow or orange berries, poisonous to people but not to birds, borne on female trees in winter
- Grows in shade or sun in well drained soil
- Creates deep shade under its canopy