(Chambersburg Public Opinion) The sale of a popular landscaping shrub that harbors deer ticks may be prohibited soon in Pennsylvania.
The state Controlled Plant and Noxious Weeds Committee is to discuss the fate of Japanese barberry at its first meeting later this month. Act 46 of 2017 established the committee to control noxious weeds in Pennsylvania.
The law currently lists 20 noxious weeds — including kudzu, multiflora rose and poison hemlock.
“Japanese barberry is a great example of a plant that should have been included in the noxious weed list long ago,” said Nathan Hartshorne, a representative on the Mid-Atlantic Invasive Plant Council. “It is already listed in many states, and Pennsylvania needs to follow.”
What should you know about the plant?
Barberry has quietly gone about its takeover since being introduced in 1875 to Boston’s Arnold Arboretum.
“Not much feeds on the plants, so they provide little input in the ecosystem,” Hartshorne said. “Even deer avoid eating the plant, which allows it to spread as dense thickets through woodlands, preventing native trees from growing.”
The thorny plant offers protection to deer mice, the primary winter host for deer ticks, which spread Lyme disease to humans. Barberry’s dense foliage also traps humidity that ticks need to stay active. A University of Connecticut study found in 2011 that the number of ticks carrying the Lyme spirochete were more than 10 times greater in barberry thickets than areas without the bushes.
Japanese barberry makes a home for itself by changing the soil chemistry. The altered conditions repulse native plants.
“As an invasive, barberry has been around awhile and, at least compared to some of the newcomers we are dealing with, does not seem to be nearly as explosive in how quickly or completely it dominates an area compared to, say, mile-a-minute, stilt grass or Japanese Aralia,” said Roy Brubaker, district forester at the Michaux State Forest. “I think if we could just keep people from planting the durn stuff as an ornamental, it might actually be one of the ‘manageable’ plant pests our forest systems are currently coping with.”
Michaux’s forest management team took a stab at controlling barberry about three years ago near Pine Grove Furnace State Park, Brubaker said. The team used grant money to buy special equipment to apply “extremely targeted herbicide.”
The team returns spring after spring and sprays from the road edges in, while trying to limit collateral damage to desirable plants, he said. The barberry has not been growing back as expected from seeds or underkill. Desirable vegetation seems to be filling in.
“In spite of how incremental the progress has been, we feel it has been a success,” Brubaker said.
What can the committee do?
A new law gives the committee the administrative power to ban the distribution, cultivation and propagation of a noxious weed in Pennsylvania without a permit. The committee could also require the elimination of the weed on a property.
Pennsylvania has two classifications of noxious weeds. Class A weeds are not widespread, and the aim is to eradicate them. Class B weeds are widespread and cannot be feasibly eradicated. The committee can require control of Class B weeds or offer help in controlling them.
The state agriculture department for years has been offering help to property owners in tackling giant hogweed, currently a Class A weed in Pennsylvania, according to Pennsylvania Agriculture Department spokeswoman Shannon Powers. The weed, whose toxic sap can burn, grabbed headlines in June after it was discovered in Virginia.
Pennsylvania has been working to eradicate giant hogweed since 1990, years before there was a toxic weeds list, according to Powers. The state agriculture department became involved partly because of the danger in removing the weed.
Pennsylvania once had more than 500 sites and currently has 40 sites, most in northwest Pennsylvania and most with just one plant. None are in Franklin or Cumberland counties.
People who suspect they have giant hogweed are encouraged to report it to the state botanist who will remove it and follow up for three years.
The state noxious weeds committee holds first meeting at 10 a.m. on July 24 in the Department of Agriculture building, 2301 N. Cameron St., Harrisburg. A complete agenda is not available, but Japanese barberry is on the agenda, according to Powers.
She said she did not know whether the meeting was open to the public.
The committee has 13 members, including majority and minority chairs from the House and Senate agriculture committees. Other members represent the farming community, horticulture industry, state game and fish commissions and the state agencies of agriculture, conservation and natural resources, transportation and environmental protection.
Alternatives to the shrub
Barberry will not be eradicated through regulation, but proactive laws can mitigate its impacts, according to Hartshorne.
“By encouraging it, by planting it and selling it, we continue to make the situation worse,” he said. “We certainly want to support our horticultural trade in Pennsylvania, but there are many alternatives. Instead of promoting barberry which hurts Pennsylvania timber and game, we could sell chokeberry, holly, pepperbush, meadowsweet, and so many others.”
Michaux is replacing killed-off barberry with native winter food sources such as scrub oak, Allegheny chinquapin, winterberry holly, American hawthorne, blackhaw and other viburnums, wild grape, dogwoods, aspen and birch, Brubaker said.
The red berries of the barberry are recognized as a “survival” winter food for grouse and other birds, such as cardinals, Brubaker said. Overwintering grouse are all but non-existent in Michaux.
“We want to make sure we don’t make winning the battle against barberry our final act of benign neglect against our state, and other, wild birds on this mountain,” Brubaker said.
Barberry posed another puzzle for the foresters after they cleared the encroaching invasive from around a large patch of pink lady slipper orchids.
“We patted ourselves on the back for being able to successfully inventory the over 2,000 blooming individuals in the patch the next year,” Brubaker said, “only to have a couple local deer mommas totally decimate the population the following year. So to take the place of the barberry, we had to erect a deer exclosure fence from materials we salvaged from one of our dismantled timber sale fences.”