Invasive Plants, Pacific Northwest
English Holly grows all over the Pacific Northwest and I personally have seen this tree in areas that have hardly been tread by man and yet, there they are. The problem is that many birds love the berries from these trees and after eating, the seeds are deposited in their droppings to all areas of the coast.
Holly is a small broad leaf evergreen tree that can grow up to 20 meters high. Red berries are found on the female trees.
It is native to the British Isles and southern and central Europe. Grown as an ornamental in North America, it has escaped into forested areas where it grows in shade or sun in well drained soil.
Holly 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 water loving plant and will draw in as much as it can with its thick and large root system, thus preventing local native plants from obtaining enough water or the nutrients they need that is 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 a copious like re growth from the stump. Applying herbicide to the cut stump is about the only way to stop the re-growth.