Twinberry

Lonicera involucrata (Caprifoliaceae) is a deciduous shrub native to a broad range across North America from Alaska to the southwestern United States and east to the Great Lakes and Quebec, growing primarily in mountains and coastal zones. It reaches about 13 feet tall with an erect to spreading habit. Young stems are squarish in cross-section. Yellow flowers tinged with red (about 13 mm) appear in pairs from June to July, followed by distinctive paired dark purple to black berries (about 5 mm).

Twinberry grows in full sun to part shade and prefers moist to wet sites, though it adapts to drier conditions. It tolerates a broad pH range (4.5 to 8.5). The paired berries attract birds, and the flowers draw hummingbirds and butterflies. Documented problems include powdery mildew, root rot, yellow vein virus, and aphids. It blooms on old wood, so pruning should follow flowering. The species works well in riparian restoration and wildlife plantings. Hardy in Zones 4a to 8b.