Sale of Two Popular Landscape Plants Now Banned in PA

Jan 27, 2022

By Lois Miklas

In fall of 2021 two popular landscape plants were added to the Pennsylvania Department of Agriculture's list of noxious weeds: Japanese barberry (Berberis thunbergii) and Callery, or 'Bradford', pear (Pyrus calleryana) . According to Pennsylvania law a noxious weed is "a plant that is determined to be injurious to public health, crops, livestock, agricultural land or other property." Most plants on the noxious weed list are recognized nuisances (for example, Canada thistle, poison hemlock, and stiltgrass). However, Japanese barberry and Callery pear trees have long been promoted for residential and commercial landscaping. Their placement of the noxious weed list includes a phased plan for making their propagation and sale in Pennsylvania illegal.

Why is Japanese barberry a problem?

Known for its dark red foliage and deer resistance (due to thorns), this seemingly well-behaved shrub forms dense thickets in natural areas, crowding out diverse ecosystems of native plants. Japanese barberry has berries that many people do not even notice. Birds eat these berries and then disperse them in meadows, pastures, and woods. Japanese barberry also spreads when its branches touch the ground and root. Some research indicates that Japanese barberry harbors the black-legged tick, a major source of Lyme disease.

Why are Callery pear trees a problem?

The Callery pear was developed as a street tree in the mid-20^th century; landscapers and residents embraced the trees' flush of white blossoms in spring, rounded canopy, and attractive fall color. Despite their pleasant appearance, they have proved to be very susceptible to wind damage. Like Japanese barberry, Callery pear trees originated in Asia and have escaped cultivation in North America, aggressively taking over natural areas. Birds and small mammals consume the small, hard pears—inedible to humans—and distribute the seeds. The trees also spread through a shallow root system.

What can residents do?

By fall of 2022, it will no longer be possible to purchase Japanese barberry or Callery pear trees in Pennsylvania. At this time residents are encouraged, but not required, to remove existing plants. Though sterile cultivars of Japanese barberry may be available soon, Master Gardeners recommend that residents choose native plants as replacements or additions to the landscape.

Native plants to replace Japanese barberry:

Ninebark (Physocarpus opulifolius) has burgundy foliage and peeling bark that adds winter interest.
Smooth hydrangea (Hydrangea arborescens) is a native version of the popular shrub.
Virginia sweetspire (Itea virginica) sports cylindrical, aromatic spring blossoms and lovely fall color.
Inkberry (Ilex glabra) is a broadleaved evergreen in the holly family that has a hedgelike quality similar to Japanese barberry.

Native, spring-blooming, replacements for Callery pear:

Serviceberry (Amelanchier canadensis) has lovely, white spring blossoms and berries attractive to birds.
Redbud (Cercis canadensis) is known for its purple spring flowers; white cultivars are also available.
Crabapple (Malus, spp.) Though both native and exotic varieties of crabapples are available, according to Doug Tallamy in Bringing Nature Home, natural hybridization has helped make most crabapples friendly to native wildlife.

Source : psu.edu

Video: The 15-Year Bet Behind Every New Variety!

Canada is trying to decide how much agricultural research capacity it can afford to lose. Brian Rossnagel believes the better question is whether the country can afford to rebuild it.

The longtime barley and oat breeder makes the case with a simple fact about his profession: the consequences of today’s decisions may not become visible for 10 or 15 years.

“Pick the right parents. That’s the biggest thing,” Rossnagel says. “If you pick the wrong parents, you’re not going to get anywhere—and you don’t know that until 10 years, 15 years later.”

That warning carries particular weight as Agriculture and Agri-Food Canada moves to reduce spending and streamline parts of its science operations. The department’s 2026–27 plan anticipates the loss of approximately 665 positions by 2028–29 and says some research will be reduced where capacity exists in academia or industry. AAFC says the changes will make its science operations more cost-effective over the long term.

For Canada’s seed industry, Rossnagel’s career illustrates what is at stake.

This fall, the retired University of Saskatchewan breeder will be inducted into the Canadian Agricultural Hall of Fame. During his 35-year career at the Crop Development Centre, he helped develop more than 100 barley and oat varieties, including CDC Austenson—one of Western Canada’s most widely grown feed barleys. His induction recognizes not only those varieties, but the collaboration and research system that made them possible.

Rossnagel is quick to emphasize that none of it was the work of one person.

“The first thing I thought about was all the other people who contributed to whatever success I and my program had over the years,” he says. “We know that it’s not an individual who does this. It’s a group—a team.”

That team extends well beyond the breeder whose name appears beside a variety. It includes technicians, pathologists, quality specialists, statisticians, regional testing sites, seed growers and industry partners. It also includes the breeders who came before and those who will carry the germplasm forward.

CDC Fraser barley, for example, moved through three breeding careers. Its parents came from Brian Harvey’s program. Rossnagel advanced the material after Harvey retired, and Aaron Beattie later guided it through registration and release.

That kind of handoff is normal in plant breeding. The person who makes the original cross may never see the resulting variety reach farmers.

It also explains why lost research capacity cannot simply be switched back on when budgets improve.

“If you shut it off, it’s very, very difficult—and particularly costly—to start it up again,” Rossnagel says. “If you have to start from scratch, it’s going to be at least 10 years before anybody notices whether you’re getting anything done or not.”

The concern is not simply how many experimental lines Canada can process. Modern equipment, statistical tools and genetic technologies allow today’s breeding programs to evaluate tens of thousands of lines—far more than Rossnagel could handle when he entered the field in the early 1970s.

But efficiency and automation do not generate every idea.

“If you pare back down, and instead of having six or seven individual scientists concentrating on wheat breeding, you go down and say three people could handle all this, well, that’s half the ideas gone,” he says. “Particularly if you happen to lose the three people who had the really neat and innovative ideas, boy, that’s a problem.”

It is a timely distinction for Canadian agriculture. Consolidating programs may preserve the volume of material moving through a system, at least initially. It may not preserve the diversity of thinking, regional knowledge or willingness to pursue unconventional crosses.

That regional knowledge matters because Canadian agriculture is not one uniform production environment. A variety suited to southern Alberta may face different disease, moisture and maturity pressures than one grown in Manitoba, Ontario or Atlantic Canada.

“Agriculture is applied biology,” Rossnagel says. “Biology, all around the Earth, moves from the poles to the equator. It does not move from Newfoundland to B.C. like politics do.”