Stop the spread

Invasive species are taking their toll on both residential and commercial properties with damages in the tens of billions of dollars, says Rex Bastian, regional technical advisor for The Davey Tree Expert Company based in Kent, Ohio. Exotic and invasive insects and plants, spurred on in part by climate change, continue to spread from region to region across the country.

There is increasing concern and attention in the way of economic assistance from the federal government, and many states, to combat the problem of invasive species which they say cause harm to the economy, environment and human health.

Exotic species are those that are found outside of their natural habitats. These often become invasive species because they don’t have natural predators or competition to keep them from multiplying and spreading rapidly. They are often so successful that they crowd out native species.

“We call them invasive because by the time we realize they’re here and causing damage, it’s too late,” says Ben Hamza, director of technical operations at TruGreen. He cites emerald ash borer, which has been found in most states east of the Mississippi and on into Canada, as a good example. By the time it was discovered in southern Michigan in the summer of 2002, it had already wreaked havoc on mature stands of ash trees.

Stock your arsenal.

Invasive species pose a challenge for landscapers, arborists, lawn care operators and other green businesses.

Fortunately, there is a war chest of information out there. Since invasive species are specific to a particular region, the first place to look for information is locally. Green industry professionals in the Midwest and other portions of the country should look for a Cooperative Invasive Species Management Area (CISMA), or Cooperative Weed Management Area (CWMA) office.

CISMA is a fairly new organization supported by public and private groups. The cooperative was formed to bring various local and regional groups together to coordinate information and resources on invasive species.

“First, see if there is a local invasive species cooperative,” says Nick Cassel, coordinator for the Three Shores CISMA in Michigan. “If not, the next thing would be to contact your department of natural resources office or U.S. Forest Service. The U.S. Forest service is always promoting invasive species information.”

Experts in eradication.

Equipped with the knowledge they need about invasive species, LCOs can do a lot to help control and eradicate them while servicing their customers. In regard to insects, it’s a matter of identifying the species first and then finding the appropriate applications to control or eradicate them.

Hamza attends seminars and meetings to find the most up-to-date and effective ways to treat different pests. He adds that it’s important to follow recommended procedures to deal with the pest to avoid harming beneficial organisms since poor management of pests could cause more problems than simply doing nothing.

Hamza says examples of common mistakes are off-target spraying like letting liquid trickle or drift into a stream and spraying too much or at the wrong time of year and killing beneficial insects, especially pollinating bees.

By saving trees from emerald ash borer with trunk injections and systemic pesticides, landscapers and arborists are protecting an investment since ornamentals contribute to the value of a property. Furthermore, treatment can be cheaper than removal.

“There is a value associated with a property,” Hamza says. “The beauty of the tree, once it’s gone it lessens the value of the landscape.”

Pesky pests.

There are many other pests that are wreaking havoc on the environment and require our attention. Some of these, such as the bark borers out west, including the native mountain pine beetle, pose a larger threat to the natural environment outside of urban landscapes, and need to be treated. Companies like Davey and TruGreen are working with residential clients and municipalities to try to get a handle on these pests.

Along the eastern seaboard, people are concerned about the advance of the southern pine bark beetle. For years it was considered confined to the southern states, now it is marching up the coast. And citrus growers in California and Florida are worried about the Asian citrus psyllid, which can spread huanglongbing, a fatal disease among citrus trees.

Warmer temperatures are not only contributing to the spread of invasive species, but are also stressing plants, making them more vulnerable to insect pressure. This is particularly apparent in the western mountain states, Bastian says.

Know your enemy.

Landscapers and nursery owners need to be aware of what is considered invasive in their region. Cassel says the problem with invasive plants, such as purple loosestrife that clogs waterways, is they drive out native species that pollinators, birds and other animals depend on for food and habitat. In addition, quickly spreading plants like kudzu alter the look of the landscape.

“If you’re driving along I-75 through Tennessee, instead of seeing beautiful southern pine trees, you see a wall of kudzu,” Hamza says.

Cassel says his organization is working with landscapers to help them gain awareness of the problem. “This is something we’re really trying to delve into because in the past, it wasn’t an avenue we approached. It is becoming very apparent that there are some of these species that people are planting or landscapers are pushing that look great in people’s yards. But a lot of these species are invasive for a reason. They don’t stay in people’s yards long.”

Cassel says landscapers can play an important role in the battle against invasive species by educating homeowners and encouraging them to plant alternatives to invasive species, preferably native plants.

“The biggest push I’d like to see is an educational component,” Cassel says. “If we can come up with a list of five or 10 species that are highly invasive then we can say ‘Hey, be on the lookout for this species and don’t support planting these.’” His office is currently working with local landscapers to educate them on what’s invasive in their area.

Education is a two-way street. Bastian says it’s important for LCOs to keep an eye on what infestations might be occurring in their area and report back to the appropriate agencies. Ultimately, though, it pays to stay informed.

“There is a wealth of information out there,” he says. “If you’re not paying attention to it, then the chance of spreading misinformation or the wrong information is greater.”