Bye-Bye Barberry

December 7th, 2021

   If you wonder why Japanese barberries aren’t in garden centers next spring, it’s because Pennsylvania has banned the sale of this popular little thorny-stemmed shrub as a harmfully invasive plant.

Barberries are being banned from sale in Pennsylvania.

   Japanese barberries have been a landscape staple for decades because they’re heat- and drought-tough, deer don’t like them, they’re compact, they aren’t commonly bothered by bugs and disease, and they come in attractive varieties with brick-red and golden foliage.

   However, these bullet-proof features also make them a dominant competitor in the wild, where their prolific seeding has caused them to elbow out most everything else in pastures, untended fields, and woodlands.

   Strike two is research at the University of Connecticut that found barberries to be a favorite host plant of black-legged ticks, which are prime transmitters of Lyme disease.

   The Pennsylvania Department of Agriculture decided that the harm to Pennsylvania ecosystems is great enough that Japanese barberries should be banned from sale in the state. We’re the fifth state to ban barberries, along with Maine, Minnesota, New Hampshire, and New York.

   Barberries have been identified as an ecological threat in at least 20 U.S. states.

   Although the ban is immediate, the department said enforcement will be phased in over two years to give growers and sellers a chance to adjust and react. As of the fall of 2023, anyone selling or growing Japanese barberries in Pennsylvania will have to immediately destroy them.

   That destruct order doesn’t extend to plants that gardeners already are growing in their yards. But the Agriculture Department is asking gardeners to voluntarily yank them anyway.

   “Carefully considering the potential impact of what we plant can prevent lasting damage that is difficult, expensive, or impossible to reverse,” said Agriculture Secretary Russell Redding in announcing the barberry ban.

   While just about everybody agrees Japanese barberry has become a leading invasive-plant problem, the complete ban was complicated by the fact that not all varieties of the species are equally invasive.

   Researchers at the University of Connecticut and North Carolina State University in recent years have developed reportedly sterile cultivars, including Crimson Cutie and Lemon Glow in the WorryFree series and Proven Winners’ Sunjoy Mini Maroon and Sunjoy Todo.

   Growers argue it’s unfair to wipe out a whole popular line of plants if varieties are available that sidestep the underlying reason for a ban.

Lemon Glow is a golden barberry that’s purported to be sterile.
Credit: Overdevest Nurseries

   Some states have addressed that by creating exemptions for sterile cultivars of banned species.

   New York, for example, has exempted four barberry cultivars from its ban: ‘Aurea,’ Crimson Cutie, Lemon Cutie, and Lemon Glow.

   When Oregon banned butterfly bushes, it allowed exemptions for more than a dozen cultivars, including ‘Blue Chip,’ ‘Blue Chip Jr.,’ ‘Ice Chip,’ ‘Inspired Pink,’ ‘Purple Haze,’ and seven cultivars of the Flutterby series.

   Pennsylvania decided to ban all barberries up front and then to consider a plan for exemptions later. That process is already in the works and leaves the door open to selected barberries returning to garden centers.

   For now, though, all Japanese barberries join such rampant invaders as mile-a-minute weed, poison hemlock, Japanese knotweed, multiflora rose, and Canada thistle on the state’s Class B Noxious Weed list.

   That list features 24 of our worst invaders that are widely distributed throughout Pennsylvania and deemed as “cannot feasibly be eradicated.”

   Also just added to that list along with Japanese barberry are Japanese stiltgrass (a grassy weed) and garlic mustard (a white-blooming annual that seeds like crazy). Neither of those are sold as landscape plants.

   Class A Noxious Weeds, such as giant hogweed, goatsrue, kudzu, and dodder, are ones that are either regionally invasive or ones with some hope of eradication.

See Pennsylvania’s full Controlled Plant and Noxious Weed List

   The barberry ban came at the recommendation of the Governor’s Invasive Species Council, an advisory panel chaired by the secretary of agriculture with members from seven state agencies, local governments, universities, industry trade associations, environmental and agricultural organizations, and county conservation districts.

   Barberry isn’t the only ornamental plant that GISC has been eyeing. Earlier this year, the committee whittled down a list of 150 weeds and invasive ornamentals to 25 that should be considered as additions to the Noxious Weed list.

   Among them are still-sold ornamentals including the popular red-in-fall burning bush, butterfly bush, Japanese maple, Norway maple, amur maple, English ivy, Japanese spirea, Chinese silvergrass (Miscanthus sinensis), Japanese and Chinese wisteria vines, four species of privets, Russian and autumn olives, European barberry, glossy and common buckthorns, wintercreeper euonymus, empress tree (Paulownia tomentosa), and five species of non-native honeysuckles.

These callery pears have seeded into this untended roadside area.

   Absent from that list is another tree that a lot of people think ought to be banned ASAP – the callery pear. Some also would like to see heavenly bamboo (Nandina domestica), lesser celandine, and the orange or “tawny” daylily (Hemerocallis fulva) added to the ban list as well.

   Many of the above are already on some other states’ invasive plant lists.

   Making it on the GISC list doesn’t mean any of these is going to be banned, but it at least means gardeners should give pause before buying, planting, or transplanting them… especially when so many other worthy and non-invasive choices are available.

   A good planning guide is a list developed by the state Department of Conservation and Natural Resources. DCNR has an invasive plant list that isn’t regulatory but educates by listing suspect plants under three levels of concern, plus a fourth “watch list.”

   Pennsylvania also just opened a new hotline for residents to report new invasive-species sightings, which includes invasive insects and aquatic invaders. That phone number is 833-INVASIV (833-468-2748).

   You can also report invasives online.

   To report invasive plants: email the Department of Agriculture at RA-plant@pa.gov.
   To report invasive insects: email the Department of Agriculture at badbug@pa.gov.
   To report aquatic invasive species: use the Pennsylvania Fish and Boat Commission reporting form at https://pfbc.pa.gov/forms/reportAIS.htm.

   If you’re interested in what research and action is underway to combat invasive species, check out the PA iMapInvasives database.