English Holly Proposed for WA 2011 Noxious Weed List

English Holly has been proposed as an addition to the 2011 Noxious Weed List for Washington State.  The Board is requesting comments on this matter. You are invited to submit a comment
to the board and give personal observations.

http://www.nwcb.wa.gov/proposed_changes_2011.htmhttp://www.nwcb.wa.gov/proposed_changes_2011.htm

The Washington State noxious weed list is updated every year, and all Washington residents can submit proposals to add or remove species, change the class of a listed noxious weed, or to change the designated area in which control is required for a Class B noxious weed. Anyone, including citizens, tribes, organizations, government agencies, and county noxious weed control boards may participate in the listing process by submitting a proposal or by submitting testimony about proposed changes to the noxious weed list. In fact, Washington’s open, inclusive listing process is lauded by other states for its encouragement of public participation. Learn more about the listing process here. 

This year, the State Weed Board will vote on six proposed changes to the noxious weed list, following a public hearing to be held November 2 from 12:00 pm to 2:00 pm:

• Proposal to add English holly, Ilex aquifolium, as a Class C noxious weed (except where commercially grown). Read proposal here and addendum here.

Invasive and Noxious weeds pose a very serious problem to communities all over our state. English Holly has been long understood to be invasive in our community. It is a big problem here, because there are few natural controls, it grows well in shady areas, and displaces local conifers and understory.

Over the past century many local folks planted it, because it's beautiful, low maintenance and the local horticulture industry planted it for floral arrangements and shrubbery.  It can grow very tall and take  over local yards and parks quickly. In Shoreline's new Southwoods Park, for instance, in studies by Earthcorps and Seattle Urban Nature in 2007 commissioned by Shoreline Parks, English Holly was found to be...

"........ the most numerous invasive species present, comprising 92% of all regeneration in the park, at average stem densities of 3,611 stems/acre across all plots......... 

These trees can be difficult to control as they form extensive root sprouts after being cut down.  The most effective method of control is to remove the entire root while the plant is small and can be pulled.  If the plant is larger, it is possible to remove it using a weed wrench.  If the tree is too large to be either hand pulled or removed with a weed wrench, cutting the stem as close as possible to the ground and applying an herbicide such as Roundup directly to the cut portion of the stem as soon as possible is usually effective.  Due to the fact that these trees tend to root spout and have many seedlings, monitoring around the infested areas on a regular basis will be necessary for several years after removal.  It is very important not to cut the trees down without herbicide application, as this can lead to numerous root sprouts and re-growth from the stem (King County 2007a, USDA Forest Service 2005). "

Many local stewards have spent countless hours attempting to remove the bushes, large and small from local parks and yards. However, they've discovered that this can be a daunting task, to say the least.

In Shoreline, many local park stewards have worked hard at removing the bushes.

  Southwoods Preservation Group has worked for over 5 years on invasive removal projects and was instrumental in encouraging the City to make the forest a park. These efforts have not only led to the creation of a new 16 acre park, but many work parties and progress on reducing the invasives such as Holly, Scots Broom and Ivy.

Charlie Brown shows off a "weed wrench" on loan from Shoreline Parks
which is available for removing Holly and Scots Broom shrubs
Charlie has done an enormous amount of work in preserving and improving Southwoods
with work projects and personal advocacy. He has also served as a Trails Committee member for
Shoreline Parks

Many other Parks in Shoreline have stewardship groups working to remove invasives, such as 

Sunset, Hamlin, Paramount, Hillwood, Ronald Bog and Bruggers Bog and Boeing Creek Parks. 

In Seattle many groups have also taken up this challenge with the help of organizations such as Earthcorps and Cascade Land Conservancy with its Green seattle Partnership program this past weekend. They are utilizing the enthusiastic efforts of neighborhood groups and youthful energy to make a difference. 

People who want to work on these projects to remove Holly from their parks or yards, should realize that
English Holly is sometimes confused with Tall Oregon Grape, which is a beautiful northwest native plant. Oregon Grape is a great substitute for holly, and is a valuable habitat plant too.

Mahonia aquifolium
sports blue berries rather than red, but the leaves
are somewhat similar.
courtesy of King County Native Plant Guide

Olympic National Park has an article on it's website about the plant and its associated problems.
http://www.nps.gov/olym/naturescience/english-holly.htm

Ilex aquifolium

English holly was introduced to the Puget Sound region as an ornamental and later cultivated on holly farms for the floral industry. It is now an escapee threatening native habitats.

Identification:

English holly is an evergreen tree with a dense conical growth of short branches. It can grow up to 50 feet tall and one-and-a-half feet in diameter. Leaves are oval with spiny points and wavy edges; they are stiff and leathery, shiny dark green above and paler beneath. The tree’s bark is gray and smooth or nearly smooth. Twigs are greenish to purplish. Female flowers (which mature into fruit) and male flowers (which produce only pollen) are found on separate plants. Holly fruit is berrylike, shiny red, and contains four nutlets.

Look-a-likes:

• Native Oregon grape species with waxy slightly-pointed leaves could be confused with holly.

English holly was introduced from southern Europe, northern Africa, and western Asia. It is an escaped ornamental, now widely distributed. It grows from seeds and is spread by birds. It is shade tolerant and can live in undisturbed forested sites. It can displace native conifers like Douglas-fir or Sitka spruce.

 Also, King County has published an article about removal treatments.

http://your.kingcounty.gov/dnrp/library/water-and-land/weeds/Brochures/English-Holly-Fact-Sheet.pdf