English laurel (cherry laurel) identification - Prunus laurocerasus
English laurel, also called cherry laurel, is a large evergreen shrub or small tree often used for landscaping, usually as a hedge. Related to cherry trees, English laurel gets its common name from its resemblance to the true laurel tree. Native to southwestern Asia and southeastern Europe, this species has been widely introduced in Europe and North America, and has escaped cultivation in many areas, including the Pacific Northwest. This plant is commonly found in urban forests in King County, Washington and can also be found escaping into more remote areas, usually spread by yard waste dumping or by birds eating the plant's cherry-like fruits (which are not palatable to people, and can be poisonous).
Legal status in King County, Washington
English laurel is on the monitor list of the Washington State Noxious Weed List. Although it is legal to sell and grow it in Washington, English laurel is classified as a Weed of Concern in King County and its control is recommended in natural areas that are being restored to native vegetation and in protected forest lands. New plantings are discouraged especially where it could impact forest lands. For more information see Noxious weed lists and laws or visit the website of the Washington State Noxious Weed Control Board.
Description (see below for more photos)
- Tall, dense, spreading thicket-forming shrub or small tree, 10 to 30 feet tall (usually kept shorter by pruning), grows as either a single-trunk tree or a multi-stemmed shrub
- Evergreen leaves are dark green on top and pale underneath, thick, shiny, large (3 to 8 inches long), oblong, abruptly pointed at the tips, alternate on the stems, and have finely toothed edges and short leaf stalks
- Small white flowers in upright clusters (racemes) resemble cherry flowers, cup-shaped with 5 petals and fragrant, many yellow stamens
- Produces small, purplish-black, cone-shaped, cherry-type fruits, also in clusters
- Twigs green and smooth
- Poisonous parts include wilted leaves, stems, and seeds (may be fatal if eaten)
Reproduction and spread
- Reproduces through seeds, which are distributed by birds and possibly other animals
- Also spreads laterally by layering (growing roots from stems where they touch the ground)
- When cut, English laurel will sucker from the roots and re-sprout from cut stems
- Grows in sun or shade, moist or dry soils, but does best in moist, well-drained soils
Impacts and distribution
English laurel has escaped cultivation into forests and parks adjacent to developed areas and occasionally into more remote forests. According to the USDA Plants Database distribution map, English laurel is reported as naturalized in Washington, British Columbia, Oregon, and California. Here in Washington, English laurel is most common west of the Cascades.
According to the University of Washington Herbarium records, botanists have collected specimens of English laurel from naturalized populations in 7 western Washington counties, mostly around the Puget Sound area. Collected plants have varied from immature plants to flowering or fruiting trees. In some cases, the English laurel was growing as a single tree or in small, patchy populations, but in other cases, there were substantial populations noted that included a range of ages from seedlings to fruiting trees. English laurel is often found with a mix of native and non-native species.
In King County, English laurel is most commonly found invading urban parks and forests, especially in the Seattle area, but escaped populations can be found throughout the county. According to a 2006 report on Seattle's urban forests, English laurel was the second most common invasive tree species, found on 67% of study plots with an average of 46 stems/acre (English holly was the most common invasive tree found in this study).
Impacts of English laurel include out-competing native forest species such as tree seedlings and native shrubs and replacing native canopy trees over time. Very fast-growing and tolerant of disturbance and a wide range of conditions, English laurel is a strong competitor and thrives in our climate. Because it is spread by birds to remote areas, it has the potential to be a serious threat to native forest land in the Puget Sound region. English laurel is also poisonous.
- Small plants can dug up when soil is moist (take care when handling because this plant is poisonous).
- To control larger plants, cut stems and trunks by hand or chainsaw, cutting as close to the ground as possible, and remove stems to make it easier to control re-growth. Stems can be chipped and used as mulch or taken to a landfill. Leaving stems on moist ground might result in some stem-rooting, but it is unlikely, and if stems are chipped this shouldn't be a problem.
- After cutting, plants are very likely to re-grow. There are five main options for controlling the re-growth after cutting:
- Dig out the stumps including as much root as possible. To avoid regrowth, stumps should be turned upside down and soil should be brushed off roots. Mature laurel trees have deep and extensive roots so digging is labor-intensive and may result in considerable soil disturbance. If the stumps are dug up, be sure to stabilize the area to prevent erosion and replant with appropriate trees and shrubs, especially on steep slopes. For large infestations or steep slopes, digging may not be the best method.
- Monitor stems for re-growth and break off any new stems. This should be done regularly throughout the growing season over several years until the plant stops sending up new shoots. Some older plants won't re-sprout very much, but left alone, all English laurel will re-grow to some extent. Also, monitor the area for seedlings and pull them up. They are easy to spot with their thick, shiny leaves pointed at the tips. Applying mulch to the area will reduce seedling growth.
- Immediately after cutting, treat stump by painting or spraying with glyphosate or triclopyr. Read the product label carefully for rate, timing and safety precautions. Herbicides may not be allowable in all locations, so contact your local jurisdiction about permitting requirements or restrictions.
- Variations on the cut stump method that also work are frilling (chipping notches around the trunk and applying herbicide to the fresh cuts) or injecting herbicide into the trunk (this may require special injection tools). These methods can be used on large stems that have not been cut down, although it may be easier to first cut off smaller side stems and foliage to access the main trunk.
- Spray re-growth and seedlings with triclopyr or glyphosate diluted according to the product label for controlling brush. Make sure to use an appropriate surfactant and follow the label recommendations on timing and safety precautions. As stated above, make sure to follow all local, state and federal rules regarding herbicide use at your site.
What to do if you find this plant
Because English laurel is already naturalized in many places in King County and is not on the State Noxious Weed List, we are not tracking locations. However, if you know of any heavily infested forests, especially outside of the urban growth area, we would be interested in having that information. We are also gathering information on effective control methods. If you have had any success (or failures) controlling this plant, please contact our office.
It is important to stress that English laurel is produced and sold in Washington and Oregon and there are no regulations or limits on its sale or use in landscaping.
For more information
English laurel photos - click thumbnail for larger image