Japanese barberry is an invasive shrub that is native to Japan. In the 1870’s, seeds of the Japanese barberry were introduced to North America at the Arnold Arboretum in Boston. Due to the bright berries and leaves that Japanese Barberry produces, it has been widely planted across North America as an ornamental plant. The Canadian Food Inspection Agency began to regulate the import of certain cultivars of this species, as it is the alternate host of black stem rust.
Japanese barberry is densely thorned with prolific seed production well into the fall. Birds spread the seed far and wide and branch fragments can readily root to form new shrubs, resulting in this invasive often forming dense thickets. It is also capable of becoming established in a variety of habitats, including areas with partial sunlight and deep shade.
Japanese barberry can be found in North America from North Carolina and Tennessee and north into Canada where it is found with a scattered distribution in southern Ontario, Quebec and Nova Scotia.
Impacts of Japanese Barberry
- Forms dense thickets that reduce wildlife habitat, affect native plants and restrict recreational activities along trails.
- The dense growth of Japanese barberry plants shade out native species in the forest understory.
- Japanese barberry is capable of invading undisturbed forests and hybridizing with the common barberry (Berberis vulgaris, another invasive species).
- Can impact agriculture, barberry species are the alternate hosts of black stem rust, a disease capable of causing major damage/loss to grain crops.
How to Identify Japanese Barberry
- Shrub with rounded outline, usually 1 m tall, occasionally reaching up to 2 m.
- Often one of the first to leaf out in spring, with sharp spines along its many branches.
- Leaves are smooth-edged and ovate; clustering in tight bunches close to the branch.
- Flowers are yellow and bloom in May.
- Fruits are bright red, found singly or in clusters. Fruit mature in mid-summer and remain through the winter.
What You Can Do
- Learn how to properly identify Japanese barberry and how to prevent accidentally spreading this invasive species.
- Avoid using invasive plants in gardens and landscaping.
- Buy native or non-invasive plants from reputable garden suppliers. See Grow Me Instead: Beautiful Non-Invasive Plants for Your Garden.
- Learn how to effectively control invasive plant species on your property.
- Do not dispose of invasive plants in the compost pile – discard them in the regular garbage.
- Reduce the chance of spreading invasive plants and seeds by keeping pets on a leash when on trails.
- If you find Japanese barberry or other invasive species in the wild, please contact the Invading Species Hotline at 1-800-563-7711, or visit EDDMapS Ontario to report a sighting.