Wednesday, 27 December 2017

Landowner Help for Common Reed Control

Picture of standing man with common reed towering over him.

Photo by James H. Miller, USDA Forest Service, Bugwood.org

Landowners across southeastern Wisconsin know about common reed, an invasive grass that is even tougher than cattails. If this invasive species is on your hit list we have good news for you.

Description

Common reed (Phragmites australis), also called phragmites, invades moist habitats including lake shores, river banks and roadways. It has extensive rhizomes that can quickly spread underground and take over large areas. These rhizomes store energy, as a result, the plant can recover from cutting, burning or grazing. 

Common reed alters hydrology and wildlife habitat, increases fire potential, and shades native species. It can spread through root fragmentation, long runners above ground, and sometimes windblown seeds or cut stem fragments. Phragmites is on the Wisconsin DNR Chapter 40 list of prohibited and restricted species.

According to the Wisconsin Wetlands Association, Phragmites is the tallest wetland grass in Wisconsin. It grows upwards of 14 feet. Seed heads are visible from August to September, and it has a round stem, long, wide leaves. Its prominent plume-like seed head that is whitish to purplish in color. Be aware, there is a variety of Phragmites native to Wisconsin that forms less dense patches (you can generally see through the stand) and flowers earlier (July to August).

The Midwest Invasive Plant Network (MIPN) is working in partnership with the U.S. Forest Service Region 9, to host a series of 3 webinars in January and February featuring case studies of the restoration of sites invaded with exotic pest plants.

Webinar

Illustration of common reed seed head.

The first event will be on Tuesday, January 16th, 11:30 – 12:30 CST. The presentation is titled “Bridging the Gap – New Insights on Technology and on-the-ground Management of Phragmites.” The presentation will be given by Steve Apfelbaum, Founder and Chairman of Applied Ecological Services out of Brodhead, Wisconsin.

For free registration, please visit the MIPN site, and make sure the email address mipn@mortonarb.org is in your approved contacts to receive the webinar link.

Monday, 11 December 2017

Forest Killing Weed: Japanese knotweed

closeup of Japanese knotweed flower

Japanese knotweed, also called Mexican bamboo grows up to 15 feet tall.

What would you say if somebody told you that a weed could crack the asphalt in you driveway, force its way through the foundation of you house and prevent maple regeneration in your woodland? The weed is called Japanese knotweed and it is here in Wisconsin.

Picture of silver maple floodplain forest community.

Healthy silver maple lowland floodplain forest community with native ferns as ground cover. Courtesy of the Maine Department of Agriculture, Conservation and Forestry.

Researchers in Pennsylvania found that the invasive plant, Japanese knotweed (Fallopia japonica), can grow so thick in river floodplains that it can prevent silver maple seeds from taking root and regenerating the forest canopy.

It appears, however, that poison ivy may be a competitor for Japanese knotweed. And unlike knotweed, poison ivy seems to be much more of a team player. Areas with high density of poison ivy had more diversity than those dominated by knotweed. Not withstanding the problems it causes humans, poison ivy seems to be  better neighbor for stream bank plants.

Japanese knotweed is a serious threat in wet soils, especially in lowlands and along riverbanks. Knotweed is also found along bike paths in Madison and roadways in Iowa County.

Knotweed Control

Getting rid of Japanese knotweed is very tough. It grows up six to ten feet tall on hollow stalks that die back in the winter. Knotweed produces a large amount of seed that sprouts really well. High water and even mower decks can easily spread seed or small pieces of cut stalks; both of which can start an whole new infestation. Knotweed also spreads through underground roots called rhizomes that can grow up to fifteen feet deep and twenty feet horizontally in a single year.

Kill very small patches by covering with black tarps that must be held down in place and cover an area fifteen feet wider than the patch itself to keep the roots from creeping out around the edge. The tarps must be left in place continuously for at least three years. This approach does not work for most situations.

Use a combined approach to attacking your Japanese knotweed problem. Cut down in June when the plants are around knee high. This removes stored nutrients from the roots and weakens the plant. Carefully bag and remove EVERYTHING and burn it completely or take it to a commercial landfill. Every small piece of stem that contains a node (where the leaf and stem meet) can form a completely new plant. NEVER take cuttings to a compost facility or place them on a home compost pile.

Repeat the process of cutting, bagging and removing all stems, leaves, flowers and seeds in late August or the first week of September. Again, burn the cuttings completely or taken them to a commercial landfill.

Three weeks later, spray the plants that have re-sprouted with Glyphosate (commercial products include Roundup) according to the label directions.

Japanese knotweed requires three years or more following the same regime to totally eliminate the problem.

Find More Help

For more information about managing Japanese knotweed, check out the Wisconsin DNR Invasive Species factsheet or the UW Extension bulletin.