Japanese barberry

Japanese barberry is a deciduous shrub that grows 2- to 6-feet tall. It has bright-red berries, small teardrop-shaped leaves, and thorny twigs. The species was introduced for landscaping, often as a barrier hedge.Leaf color ranges from blue green to green to dark reddish-purple. Japanese barberry prefers full sun to part shade but can reproduce and succeed in full shade conditions. The berries mature in late summer and early fall and persist into the winter. 

 Birds and small mammals disperse the Japanese barberry fruit, but it also spreads by root expansion. It invades fields, field edges, wetlands, and forests, displacing native plants. The plant also alters soil acidity and nitrogen levels, reducing the biological activity of native soils.

The species resprouts vigorously after cutting, so control by cutting requires frequent repetition over several seasons. Annual mowing may suffice to prevent the species from colonizing fields. Small plants can be hand pulled but use thick gloves to protect against their sharp thorns. Japanese barberry can be effectively controlled with a foliar spray of glyphosate-based or triclopyr-based herbicides. Applying herbicide to freshly cut stems may be difficult because most barberry plants have multiple stems. Always read and follow the directions on the label when using herbicide.

In Newburyport’s yard waste center, any cuttings should be contained in a brown paper leaf bag with a closed top and placed in the designated location per the attendant or cuttings may disperse and reestablish. You may also call the Sustainability Office at 978/499-0413 to get advice on the best disposal options for invasive plant cuttings.