Feral Holly

Ilex aquifolium

Family: Aquifoliaceae

Other Common Names: English holly
Weed class: monitor list
Year Listed: 2012
Native to: Asia, Europe and Northern Africa
Is this Weed Toxic?:

humans

Legal listings:

Though holly is not listed as noxious in Washington, many Washington counties and municipalities, as well as other locations around the Pacific Northwest consider this a highly invasive and damaging plant to the environment and natural resources, and actively work to control and manage populations.

Why Is It a Noxious Weed?

This plant is on the monitor list - it is not a listed noxious weed in Washington. Please contact its sponsor Tom Erler at terler@kingcounty.gov to report locations or for more information.

How would I identify it?

General Description

This shrub can get as tall as 30 feet, and can dominate the understory of Washington's native forsest stands.

Flower Description

Female plants have small, white to light green flowers that have 4 round petals. Male plants non-descript light green to white round shapes with 4 anthers coming from the center. All the flowers grow individually and directly from the branches, on very short stems.

Leaf description

Holly's leaves are lobed, ending in sharp points. They are deep green and covered in a waxy coating.

Stem description

Thick, woody stems that start off olive green and can age to brown green.

Fruit Seed Description

Bright, red berries, which are popular with birds.

May Be Confused With

Our native Oregon grape species also have spiny leaves and tend to grow in forest understory. Even tall Oregon grape does not get nearly as tall as holly does. All Oregon grape species have yellow flowers and make blue to black berries. The spines on holly leaves tend to alternate between pointing up and pointing down, while Oregon grape leaf spines all point out or up.

Where does it grow?

Healthy and disturbed forest understories, riparian areas, tree farms, tree plantations, and just about anywhere that is shady, in a variety of soil types. Will produce more seed when exposed to light.

How Does it Reproduce?

Seed spread by birds, as well as vegetatively, when stems and branches have access to moist soil.

How Do I Control It?

Young plants can be pulled out, but mature shrubs are very difficult to control. Cutting will result in the stem or stump sprouting. Herbicide can be effective when used over many years, but the expensive injection method is the most effective.

Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.