Weeding out invasive plants

Though there are many invasive plant species in Ohio, three are getting attention through a Southeast Ohio program that targets them for removal.

The Southeast Ohio Noxious and Invasive Weed Treatment Program was created by the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) to battle spotted knapweed, autumn olive and the tree of heaven, all three of which have become problems for Washington County and surrounding counties.

The seven Southeastern Ohio counties affected by these plants are: Belmont, Guernsey, Monroe, Morgan, Muskingum, Noble and Washington. Jay McElroy, area resource conservationist for the NRCS in Southeastern Ohio, said through the Environmental Quality Incentives Program, financial assistance is available for landowners in these counties.

“We have an application process,” McElroy said. “It’s a competitive process. People have to apply (through their local) NRCS field office. We’ve got $150,000 available right now.”

The application process opened up May 20 and no applications had been submitted to the NRCS as of Monday afternoon. The deadline to submit an application is July 18.

McElroy said that all three species are on the move in Washington County and surrounding counties and one started out as a good thing.

“The autumn olive is a legume type bush,” he said. “It was planted in the early 60s to 70s for (strip mine areas). It was a great habitat and stabilized the soils.”

Levi Morrow, agriculture and natural resources program director for the Washington County Ohio State Extension office, added that the autumn olive was great for wildlife.

“The autumn olive can grow in wet soil and very poor soil; it’s a very adaptive plant,” he said. “It provides a great wildlife habitat but it does spread very fast.”

McElroy said despite the good the plant did in the past, it’s taking over.

“It’s very similar to the multiflora rose (another invasive species),” he said. “What’s occurring is the birds eat the berries of the autumn olive and transport the (seeds). They can take over pasture fields if not controlled…They’re becoming a big nuisance.”

McElroy said the spotted knapweed has an effect that gives off chemicals which halt the growth of other plants.

“It has an allelopathic effect…where the roots give off a chemical to kill the plants around it,” he said. “Each plant can have 1,000 to 1,800 seeds a year. It makes it more favorable for the seeds that fall to germinate and grow.”

The most affected plants are pasture and hay grasses, which McElroy said can cause animal migration because many don’t like to graze on the plant, most especially elk and cattle.

McElroy said the tree of heaven is more temperamental than the other two plants.

“It’s a tree that grows by extending out from the root system,” he said. “It spreads based on stolons. If you injure the main tree, it will send out five more trees to grow in its place. They occur in clumps in pasture fields.”

Rick Gardner, chief botanist for the Ohio Department of Natural Resources’ Division of Natural Areas and Preserves, said that with each of the plants, grasslands are the most at risk areas, but other native trees are in danger too.

“The tree of heaven (has the most) impact to natural areas; it displaces our native trees,” Gardner said. “It can…replace the canopy. Our native maple and oak (trees) we need for wildlife are displaced. Southern Ohio has the worst infestation. The Ohio River (area) is the worst.”

Morrow said the three plants are very difficult to get rid of.

“Those three species in particular have become a large nuisance in our area,” he said. “They are devastating to crop land; they can be pretty destructive to those grounds. They’re really hard to stay on top of because (when they were newly introduced to Ohio) they didn’t think them that much of a threat but they take over.”

McElroy said to get rid of each one requires a little bit of mechanical means with some chemicals.

“The spotted knapweed requires mowing and chemical treatment,” he said. “The autumn olive, we like to mechanically mow it down and then come in with a chemical. The tree of heaven, try not to injure the main tree. Start from the roots and the base of the tree and go 18 to 24 feet around the tree with an application of chemicals.”

McElroy said the autumn olive is heavily infiltrating the Seneca Lake region and into Woodsfield.

“Belmont (County) has the worst population of autumn olive I’ve seen,” he said. “You’ll find (it) in Washington County. It’s spread throughout Southeastern Ohio. The tree of heaven you can find on almost every farm.”

He added that the most costly of the three is probably the autumn olive because it is most often found in thick, dense patches.

Morrow said early detection is imperative with these three invasive species.

“The simple fact is if you start with one plant, it will cause an issue in five years,” Morrow said. “ID (the plants) early and get it taken care of early…If you can get (the plants) removed that would be the best way to keep (them) from spreading.”

Likewise Gardner said early detection is key, saving landowners a lot of problems.

“Early detection is the key,” he said. “It saves you a lot of time and effort. A lot of times when you start to notice it, it’s usually too late.”