Saturday, February 26, 2011

Biological control of Mile-a-minute vine – a vicious invasive species

UD entomologist Judy Hugh-Goldstein with her nemesis, mile-a-minute weed (Persicaria perfoliata)
picture from:
    I am delighted to have been able to attend the Mile-a-Minute Biological Control Cooperators Meeting held at the University of Delaware on February 24th(, 2011(agenda with links to PDF versions of talks). Mile-a-minute weed, Persicaria perfoliata (L.) H. Gross is a viciously charismatic vine that arrived from Asia in the 1930s in a Pennsylvania nursery's seedling production. Charismatic because it can leap tall trees in a single season hiding all that it touches in a lush green mound of dense twisted thorn filled vegetation tangle, mile-a-minute weed is viscous because of its spine or thorns that punish unsuspecting people who dare try to pull it or those who simply brush by unaware – something that happens only once - awareness is painfully prompt.

    The Biological Control of Mile-a-Minute Weed website has a very good description of the "… prickly, branching, annual vine that germinates in early spring, usually in April or May in the mid-Atlantic region." The mile-a-minute weed is an invasive species that no one loves and therefore is a target for control opportunities and eradication efforts when practical. The invasive plant is a vine that can grow up to 18 feet in one season. We are fortunate in some sense that it is an annual, and therefore must reseed itself each year. Growing best in full sun, its iridescent blue berries can survive at least five year creating a seed bank that defies short term control solutions.

    Enter the possibilities of biological control and the work of Dr. Judy Hough-Goldstein and her research team as well as their collaborators across the region. Housed at the Dept. Entomology & Wildlife Ecology at the University of Delaware. Biological control is a cost effective as well as very efficient way reducing the impact of invasive species populations. Working with state departments of agriculture and natural resource as well as federal partners such as USDA APHIS, a highly specific insect from the native range of the invasive
mile-a-minute plant has been successfully introduced in the mid Atlantic states and is already munching its way thorough large areas of the nasty, prickly invasive vine.

    The exotic Asian weevil, Rhinoncomimus latipes, has established through carefully controlled release programs on mile-a-minute weed. Wherever it has been released it has reduced mile-a-minute cover and biomass. The weevil has also reduced mile-a-minute seed production, and where there are competing plant species a high death rate can occur. It is worth noting that as in gardens, simply removing a pest is not the end of the story, for once mile-a-minute vine or any weed, for that matter, is reduced or eliminated another weed is sure to take its place. Gardeners avoid this by constant maintenance and sophisticated competitive planting schemes. Any control whether biological, chemical or mechanical, therefore is a long term project, not a one time quick fix.

Sunday, February 13, 2011

The Wicked Inconvenience of Invasive Golden Bamboo

Selected Images from
    One person's simple solution to a landscape problem is another person's complex ecosystem challenge. Because as the US Forest Service notes "Golden bamboo thrives in full sun in all but the hottest climates where it requires some shade, it will grow in sparsely wooded secondary forests. Furthermore vigorous growth and spread is seen in moist, deep loamy soils. In habitats less than ideal, it will continue to grow and spread at a diminished rate." These traits make it a perfect choice for those who want a fast growing, impossible to kill,  quickly spreading property barrier that works effectively to shield against noise and visual distractions. Moreover, even non gardeners can successfully plant and grow a lush stand with no extra work as golden bamboo offers an attractive, easy, quick inexpensive fix to many landscape challenges. For all these reasons golden bamboo can be an immediate, cheap landscape solution.

    However, according to, Phyllostachys aurea Carr. ex A.& C. Rivière "Golden bamboo is a perennial, reed-like plant that can reach heights of 16 to 40 ft. (5-12 m). The canes (stems) are hollow with solid joints and can be 1 to 6 in. (2.5-15.2 cm) in diameter. Leaves are alternate, 3-10 in. (7.6-25.4 cm) long and 0.25-0.75 in. (0.6-1.9 cm) wide. Flowering is very rare (maybe once every 7 to 12 years). Plants spread by rhizomes. Infestations are commonly found around old homesites and can rapidly expand in size. Golden bamboo can form dense, monocultural thickets that displace native species. Once golden bamboo is established, it is difficult to remove. Golden bamboo is native to China and was first introduced into the United States in 1882 for ornamental purposes."  The aggressive displacement of native or beneficial species, whether in managed gardens or in natural areas, is extensive and unrelenting.

    Aside from the issues of supporting the local native ecological system on one's own property, the issue becomes one of externalization of costs onto another's landscape. There seems to be an idea that one may plant or do anything on his or her own land, whatever the effects, both ecological and aesthetic, that may impact another's property. That world view is perceived as natural and therefore permissible. If someone plants golden bamboo and it spreads off from his property, should he not be held liable for the mitigation of damage, and the abatement of the intrusion? In other words, if a person has the right to plant any plant does he have the right to allow any natural predilections of unconstrained exotic species to move off the property to go uncompensated? Why is it that planting a particular plant is a human activity but as soon as it negatively impacts a neighbor's land then  recourse is made to defend its spread as natural even though the original planting was anything but natural?

    This dichotomy of desires is a part of what I call the wicked inconvenience of invasive species. That stakeholders approach invasive species with radically, sometimes absolutely, different world views is a crucial challenge in the effort to bring parties to the table, and even, once the interest groups arrive, given "the information needed to understand the problem depends upon one's idea for solving it", the conversation may rapidly degenerate into hardened, contentious disagreement of a subjective and very ad hominem event. Neighbors pitted against neighbors can be the result of the inevitable spread beyond the original planting site of golden bamboo when no strategy was put into effect for long term control. The lack of a plan is inherent in the original planting choice which called for quick simple solutions. Simplification of complex ideas arise from a desire to avoid short term time consuming and possibly costly efforts and leads to expensive long term complications.

Saturday, February 05, 2011

Native Plants the Topic at the Next Fergie’s Gardeners Meeting in Maryland

Native Plants the Topic at the Next Fergie’s Gardeners Meeting

On February 8, at 7 pm at the Farmhouse,  Fergie’s Gardeners is sponsoring a panel presentation on Gardening with Native Plants.   Our expert panelists are Linda Keenan, Vice President of the Maryland Native Plant Society, Ann Bodling, Naturalist at Alice Ferguson Foundation and Kathleen Litchfield, Landscape Designer for Petro Design/Build.   This is a perfect opportunity to hear from the experts, get some answers to your questions, see your neighbors and begin planning for spring planting.  
There is no cost to attend. Light refreshments will be served.