Gardeners Have Hand in Invasive Species Control

  • Centaurea diffusa a.k.a. Spotted knapweed. Introduced in the late 1800's, knapweed can reduce diversity in the region's prairies. (Photo courtesy of the USDA)

Gardeners have been ordering new plants and digging in the dirt this spring, but if they’re not careful, they could be introducing plants that can cause havoc with forests, lakes, and other natural areas. Gardeners can’t count on their suppliers to warn them about plants that can damage the local ecosystems. In another report in the series, “Your Choice; Your Planet,” the Great Lakes Radio Consortium’s Lester Graham reports:

Transcript

Gardeners have been ordering new plants and digging in the dirt this spring, but, if
they’re not careful, they could be introducing plants that can cause havoc with forests,
lakes, and other natural areas. Gardeners can’t count on their suppliers to warn them
about plants that can damage the local ecosystems. In another report in the series “Your
Choice; Your Planet,” the Great Lakes Radio Consortium’s Lester Graham reports:


Gardening, especially flower gardening, seems to get more popular all the time. Maybe
it’s because the baby-boomers have all reached that age where they’re beginning to
appreciate stopping for a moment to smell the roses.


That’s fine. In fact if gardeners plant the right kinds of plants… it can be great for
wildlife. There are all kinds of guides for backyard natural areas.


But… in some cases… gardeners can unleash plant pests on the environment.


Katherine Kennedy is with the Center for Plant Conservation. She says almost all of the
problem plants that damage the native ecosystems were planted with good intentions…


“I don’t believe that any invasive species has ever been introduced into the United States
on purpose by someone who willingly said, ‘Oh yeah, this is going to be a problem, but I
don’t care.’ They’ve almost all been inadvertent problems that were introduced by
someone who thought they were doing something good or who thought they were
bringing in something beautiful.”


English ivy, a decorative ground cover, is now killing forests in the Pacific Northwest…
kudzu is doing the same in the southeast… and in the Great Lakes region and the
Midwest… pretty flowering plants such as purple loosestrife and water plants such as
Eurasian watermilfoil are causing damage to wetlands, crowding out native plants and
disturbing the habitat that many wildlife species need to survive.


Bob Wilson works in the Michigan Senate Majority policy office. Like many other
states, Michigan is looking at legislation to ban certain problem plants. Wilson agrees
that these plant pests are generally not intentional… but they do show that people seem to
unaware of the problems that they’re causing…


“The two most common vectors for bringing in these kinds of plants are typically
landscapers, who bring it in as a way of decorating yards and lawns, and then aquarium
dumpers, people who inadvertently dump their aquarium, thinking that there’s no
consequence to that. Before you know it, something that was contained is now spread.”


But stopping the import of pest plants is a lot harder than just passing laws that ban them.
With mail order and Internet orders from large nurseries so common, the plants can get
shipped to a local nursery, landscaper or local gardener without the government ever
knowing about it.


Recently, botanists, garden clubs, and plant nursery industry groups put together some
codes of conducts. Called the St. Louis Protocol or the St. Louis Declaration… the
document set out voluntary guidelines for the industry and gardeners to follow to avoid
sending plants to areas where they can cause damage.


Sarah Reichard is a botanist with the University of Washington. She helped put the St.
Louis Protocol together. She says if a nursery signs on to the protocol, it will help stop
invasive plant species from being shipped to the wrong places….


“And it’s up to each of the nursery owners, particularly those who sell mail order or
Internet, to go and find out which species are banned in each state.” LG: And is that
happening?
“Uh, I think most nursery people are pretty responsible and are trying to
do the best that they can. I’m sure that they’re very frustrated and understandably so
because the tools aren’t really out there for them and it is very difficult to find the
information. So, it’s a frustrating situation for them.”


But in preparing this report, we found that some of the biggest mail-order nurseries had
never heard of the St. Louis protocol. And many of the smaller nurseries don’t have the
staff or resources to check out the potential damage of newly imported plants… or even
to check out each state to make sure that banned plants aren’t being sent inadvertently.


Sarah Reichard says that means gardeners… you… need to do some homework before
ordering that pretty flowering vine. Is it banned in your state? Is it a nuisance that could
cause damage? Reichard says if enough gardeners care, they can make a difference…


“You know, gardeners have tremendous power. We, you know, the people that are
buying the plants at the nurseries – that’s what it’s all about. I mean, the nurseries are
there to provide a service to provide plants to those people and if those people have
certain tastes and demands such as not wanting to buy and plant invasive species, the
nurseries are going to respond to it. So, we’re all part of one team.”


Reichard and others concerned about the problem say although agencies are working on
it… the federal government has not yet done enough to effectively stop invasives from
being imported and shipped to the wrong areas. They say it’s up to the nurseries, the
botanists, and the gardeners to stop them. If not, we’ll all pay in tax money as
government agencies react to invasives with expensive eradication programs to try to get
rid of the plants invading parks, preserves, and other natural areas.


For the Great Lakes Radio Consortium, this is Lester Graham.

Related Links

GARDENERS HAVE HAND IN INVASIVE SPECIES CONTROL (Short Version)

  • Centaurea diffusa a.k.a. Spotted knapweed. Introduced in the late 1800's, knapweed can reduce diversity in the region's prairies. (Photo courtesy of the USDA)

Gardeners are being asked to be careful about what they plant. Invasive species that cause damage to natural areas often start as a pretty plant in someone’s yard. The Great Lakes Radio Consortium’s Lester Graham reports:

Transcript

Gardeners are being asked to be careful about what they plant. Invasive species that
cause damage to natural areas often start as a pretty plant in someone’s yard. The Great
Lakes Radio Consortium’s Lester Graham reports:


Botanists, plant nurseries and gardeners are all being asked to do a little more homework
before importing, selling, or planting new kinds of plants. Katherine Kennedy is with the
Center for Plant Conservation. She says some of the plants you mail order from the
nursery can end up being invasive kinds of plants that damage the local ecosystem…


“We are actually at a point where these invasions crowd out the native community, not
just a species or two, but the entire community. And the wildlife value falls and the
native plants are displaced. And, so, the destructive potential for a species that becomes
truly invasive is more immense than I think many people realize.”


Kennedy says you can’t count on the nursery to warn you when you order plants. She
says gardeners have to make sure the plants they’re ordering won’t hurt the surrounding
landscape.


For the Great Lakes Radio Consortium, this is Lester Graham.

Related Links