Springtime presents opportunities to learn about invasive plants
As spring begins to show its’ signs of life, the avid gardeners, farmers, and invasive species specialists prepare for another busy summer season. The long warm days ahead have us checking our to-do lists, trading seeds, and organizing weed control events around the Peninsula.
The annual spring conference of the Cooperative Weed Management Area (CWMA) will be held in Seward this year on May 4 from 10 a.m. to 4 p.m. (details below).
CWMA is a fellowship of agency representatives who are concerned with the spread of invasive plants on the Kenai Peninsula, developing management priorities for high-risk species, and sharing this knowledge with people who can make a difference on private and public lands.
Why should you care? Invasive plants have the ability to outcompete native vegetation in a variety of ways: increased frost tolerance, swift germination, affixation of nitrogen or ability to increase salt content in soils, allelopathic properties (releasing chemicals from roots to suppress surrounding plants), or creating shade thereby discouraging germination or growth of native plants. Many invasive plants are hosts to diseases and other pests that, in turn, are harmful to our local habitats.
There are over a hundred exotic and invasive plants on the Kenai Peninsula, but they vary in how harmful they actually are, the ease of managing them and how quickly they spread. Some invasive plants have been restricted for production or distribution by law because they are “noxious weeds.”
The Alaska Committee for Noxious and Invasive Plant Management (http://www.uaf.edu/ces/cnipm/) has information on regulations regarding the sale and distribution of noxious weed seeds.
The Alaska Natural Heritage Program (http://aknhp.uaa.alaska.edu/) has more information on the priority ranking and identification of invasive species. CWMA priorities and invasive species biology can be found at www.Kenaiweeds.org.
There are a few invasive plants found in every community on the peninsula that can have serious economic or environmental harm, or even threaten human health. Here are three species that are likely to have particularly harmful effects on the Kenai.
Reed canarygrass is an invasive grass that is used as forage on the peninsula. This species is a tall, robust grass that is easily identifiable in the fall, as it is the last grass to stay bright green even after mild frosts. It grows up to six feet tall, and can grow in such dense colonies that it slows stream flow in low-gradient streams, even to the point of reducing juvenile salmon habitat in the Pacific Northwest. The CWMA recently developed a strategic plan for the control of Reed canarygrass.
Orange hawkweed is another problem species in our local area. It is an ornamental plant that has proven its ability to spread beyond intended borders. It has a rosette of excessively hairy leaves, which exude a white liquid when broken, and several orange blossoms on a single stem. There are no native orange composite flowers in Alaska — so if you see one in a natural area, it is non-native and perhaps invasive.
Canada thistle is another highly aggressive plant that can be found sporadically throughout the Kenai. It can be spread in hay bales or through the sharing of farming and landscaping equipment. This invasive plant actually looks like a weed with its many thorns along the stem and leaves, and multiple pink to purple flowers in clusters at the ends of the branches. It can grow up to five feet tall and forms dense colonies with its extensive root system. Orange hawkweed and Canada thistle can cause skin and respiratory problems, restrict recreational land use, and release allelopathic chemicals that suppress surrounding vegetation.
These three species should be removed as soon as possible — this practice is referred to as Early Detection, Rapid Response (EDRR). For species-specific control options, contact your local Cooperative Extension Service, Soil & Water Conservation District or go to the CWMA website listed above. If you’d like to help out by volunteering in the second annual “Kenai Weed Smackdown,” then please join us at the Seward Middle School on June 30 from 11 a.m.-1 p.m. There will be a T-shirt for all volunteers, free lunch, and prizes for a variety of categories.
The CWMA is offering a free educational opportunity that will be held from 10 a.m.-4 p.m. at the Seward Marine Science Center (Rae building) on 3rd Avenue in Seward. The conference includes speakers from the Alaska Railroad to discuss their integrated vegetation management practices, the Alaska Sealife Center to outline their initial findings on the economic costs of invasive species prevention and control, a local greenhouse owner who promotes conscientious gardening in coastal Alaska, the Homer Soil & Water Conservation District and Kenai National Wildlife Refuge to highlight their management efforts, the Cooperative Extension Service to give us tips for understanding herbicide labels, and the Fairbanks Soil & Water Conservation District to show how to identify Elodea, a new and particularly invasive freshwater plant that can tangle up your boat props.
Please join us for this annual information-sharing event to learn how to slow the spread of invasive plants on the Kenai Peninsula.
Jen Kain is the Integrated Pest Management Specialist with the Alaska Water & Soil Conservation District in Seward. You can find more information about the Kenai National Wildlife Refuge at http://kenai.fws.gov or http://www.facebook.com/kenainationalwildliferefuge.