William Penn barberry is a broadleaf evergreen cultivar in the barberry family (Bereridaceae) derived from crossing B. verruculosa and B. gagnepainii and introduced by the Henry Foundation of Gladwyne, Pennsylvania in 1963. This shrub grows 3 to 5 feet tall and wide in a rounded form, preferring full sun to partial shade in well-drained garden soil. It can be lightly pruned in winter if needed to shape. Drought and deer tolerant. Spreads to form thickets. Birds will spread the seeds by eating the fruits. Small yellow flowers appear in clusters in early spring and are followed by red berries. The glossy green leaves turn a red-bronze in fall. Leaves and stems are spiny. It is not hardy in areas where the temperatures drop to zero F. The spiny stems make it a good choice for a privacy screen or security plant. Use in a drought-tolerant or winter garden. Insects, Diseases, and Other Plant Problems: Watch for berberis sawfly and powdery mildew. More information on Berberis .
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.