Japanese Barberry

Fact SheetTreatmentBerberis thunbergii

Invader Images

    • Japanese barberry infestation
      Japanese barberry infestation
    • Japanese barberry infestation in fall/winter
      Japanese barberry infestation in fall/winter
    • Inner bark of canes and roots can be bright yellow.
      Inner bark of canes and roots can be bright yellow.
    • Flowers are droopy, in small clusters of 2-5, pale yellow. Individual thorns occur along the canes.
      Flowers are droopy, in small clusters of 2-5, pale yellow. Individual thorns occur along the canes.

Common Look-alikes

    • Common barberry has three pronged spines, oval leaves with toothed edges, and flowers appear in droopy clusters
      Common barberry has three pronged spines, oval leaves with toothed edges, and flowers appear in droopy clusters

Identification

Appearance

Berberis thunbergii is a small deciduous shrub from 2-8 ft. (0.6-2.4 m) tall. The thin, grooved branches have thin, straight spines. Berberis thunbergii is very shade-tolerant and can form dense stands which shade out and displace native species.

Foliage

The leaves are up to 1 in. (24 mm) long and paddle-shaped.

Flowers

The pale-yellow flowers occur in drooping clusters of 2-5 and develop in mid-spring to early summer.

Fruit

The berries ripen to a bright red color and are 0.25-0.3 in. (7-10 mm) long.

 

***Check out the downloadable fact sheet above***

 

The University of Connecticut has released an excellent video series on barberry. 

Part 1: The Trouble with Barberry

Part 2: Controlling Barberry

Part 3: All About Lyme Disease

Biology

ECOLOGICAL THREAT

Barberry forms dense stands in natural habitats including forests, open woodlands, wetlands and meadows. Once established, it displaces native plants and reduces wildlife habitat and forage, increasing pressure on natives by white-tailed deer. It has been found to alter the pH and biological activity of soil. Barberry is also a human health hazard, not only because it has sharp spines, but also because it acts as a nursery for deer ticks, which can transmit Lyme disease.

Origin

Japanese barberry was introduced into the United States as an ornamental plant in 1875. It was promoted as a substitute for European barberry, the latter which was found to be a host for the black stem grain rust. European barberry was originally planted by settlers for hedgerows, dye and jam-making. Japanese barberry is still widely planted for landscaping and hedges.

HABITAT

Forest, forest edge, floodplains, meadows, fields, disturbed areas

Life Cycle

Reproduction is mainly by seed but it can root sprout and layer. Barberry produces a large number of seeds with high germination rates, estimated at up to 90%. Fruits mature from July to October and persist well into the winter. Fruit production varies with light level, but even under very low light levels (4% full sun) some seeds are produced. 

Management Options

This species is Quarantined: Class B Noxious Weed

***Check out the downloadable treatment sheet above***

Mechanical Control

Hand pull: Any time of year when the ground is soft, especially after a rain, hand pull small plants by the base of the stem. Be sure to pull up the entire root system. Hang from a branch to prevent re-rooting. For larger plants, use a wrenching tool. Continue to monitor the area every year for new seedlings.

Cut stump: Cut plants back in the fall or winter. Wrap a few layers of burlap or thick plastic over the stump and tie tightly with twine or rope. Check covered stumps periodically and cut back any new growth.

Chemical Control

Cut stump: Cut the plant 4 inches above the ground. Use a drip bottle to apply an 18-21% glyphosate solution to the stump within one hour of cutting. This is best done in late summer through winter when plants are transporting resources to their root systems.

Low volume foliar spray:  This method is used for dense populations and best left to a contractor. In the fall, when native plants are losing their leaves, spray a 2% glyphosate solution on the entire leaf surface of the plant. In order to avoid drift to native plants, spray only on calm days.

 

**Be careful not to damage or kill nearby native plants when conducting management work. And when using herbicides, always follow the instructions on the label.**