Invasive plants became invasive because people – homeowners or government workers – believed they served a useful purpose, and they deliberately planted them. The plants may have been selected for their looks or their ability to control erosion or grow fast and thus provide screening.

At the time, no one realized these plants lacked natural controls in their new regions, so would spread unmitigated. Now, decades later, the state government is stepping in to ban the propagation, sale, purchase, import or export of any plant deemed invasive, “likely invasive” or “potentially invasive” in Maine.

When the invasive-plant ban is approved – and it is expected to be, perhaps as early as the end of January – it will be long overdue. Maine is now the only New England state without some controls on terrestrial (growing in the ground) invasive plants.

At a recent Department of Agriculture, Conservation and Forestry public hearing in Augusta on the proposed regulations, the half-dozen people who testified – mostly landscapers and environmentalists – all supported the general idea, but they questioned some of the specifics.

Two things surprised me about the proposed regulations and the hearing itself: the number of plants on the list, which ran to 33 species (and with cultivars, varieties and hybrids is even longer) and the potential for the list to grow; with warming temperatures, more plants will have to be added.

Banning the sale of invasive plants is a good step, but to be effective it must be coupled with efforts to remove the invasive plants that are already taking over Maine’s forests and fields. Eradication, if it is even possible, will take a lot of time and money.

“What happened with invasive plants is that people were looking for simple solutions to complex problems,” Bob Bittenbender said at the hearing. Though his business card identifies him as a “curmudgeon environmentalist,” he has worked as groundskeeper for Maine Audubon Society’s Gilsland Farm in Falmouth, and he volunteers to document invasive plants in public spaces in Portland.

Often the people looking for those simple solutions were government employees, Bittenbender added, which prompted State Horticulturist Gary Fish, who chaired the hearing, to display posters the government printed decades ago that urge the use of the very plants now considered invasive.

Several people in the audience admitted that they had planted or sold invasive plants, acts they now regret.

Gardeners liked these plants because they grow easily, require little maintenance and are difficult to kill – all the reasons they now out-compete native plants. Wildlife, however, feels otherwise; Maine’s wildlife co-evolved with Maine’s native plants, which provide the food and shelter that make them healthiest. In addition, when a region loses its native ecosystems it loses its identity, the things that make its forests and fields look different from other places around the world.

Laura Zitske of Maine Audubon said invasive plant prohibitions are overdue and needed to prevent expense and work for foresters and farmers. The berries from such plants, she said, provide less nutrition for birds and other animals than native berries and are often diuretics, which don’t do the animals any good, either. The proposed rules might also “save stubborn people such as myself from blood, sweat and tears as they work to remove such species as Asiatic bittersweet from their own property.”

Some people worried that certain plants were left off the state’s prohibition list, while other plants didn’t belong there.

Swallow-wort, for one, is not on the list, though it is widely considered an invasive plant. But swallow-wort was introduced to Maine accidentally and has never been propagated or sold, so banning its sale or propagation is unnecessary.

Bittenbender cited several other plants he sees taking over public lands in Portland that are absent from the list. Littleleaf linden was planted along Baxter Boulevard, and he says it is spreading around Back Cove. Privet is rampant in the Riverside trolley park area. The callery pear is taking over a slope by East End School. Japanese tree lilacs are spreading. European mountain ash grows on its own in a lot of city parks, and while it might not be invasive now, when the climate gets warmer it could be.

Rugosa rose, the beach rose so common along the Maine coast, elicited some back and forth. Bittenbender argued for its inclusion on the banned list, saying it is in many state parks and spreads much faster than other roses. But Jeff O’Donal, of O’Donal’s Nursery in Gorham, countered that the rugosa is a good colonizing plant, which means that while it will spread in an area, it won’t jump great distances. Also, it requires sandy soil and full sun to grow. For those reasons, he does not consider it invasive.

He also requested an exception to the ban on all Euonymus alatus cultivars because, he said, several scientific studies offer sound evidence that ‘Rudy Haag,’ a cultivar that O’Donal propagates and sells, does not produce viable seeds.

Norway maple

Norway maple Photo by Kukuruxa/Shutterstock

Mark Faunce, a past president of the Maine Landscape and Nursery Association and an employee at a wholesale plant company, testified that he would like the regulations rewritten to reflect regional differences. He argued that plants that are invasive in the growing zone around Kittery would not be invasive, and could even be a staple, of the industry in Fort Kent.

Loosestrife  David Leaming/Morning Sentinel

Loosestrife
David Leaming/Morning Sentinel

As written, the proposed regulations give nurseries one year after they take effect to continue to sell any plants on the list. O’Donal and Faunce called for that transition time to be extended to three years, as has been done in other states adopting invasive-plant lists, because plants propagated now will not be ready for sale within a year – and the nurseries stand to lose a lot of money.

After the hearing, Fish said the Invasive Terrestrial Plants Committee that developed the regulations will review the testimony and consider possible changes.

If it makes no changes, it could vote immediately and the regulations would take effect 30 days later. Changes, of course, would delay the timetable.

I have followed the debate on invasive plants for 20 years, and I am glad that Maine is joining the responsible horticultural world and adopting a list. I’ve never heard of some of the plants on the list. Others, like multiflora rose, bittersweet and bishop’s weed (which a friend calls “the pernicious weed”), I battle regularly.

TOM ATWELL is a freelance writer gardening in Cape Elizabeth. He can be contacted at 767-2297 or at: [email protected]