Hydrangea barbara aka Woodvamp

Hydrangea barbara is a woody vine from the southeastern United States. It belongs to the hydrangea family, Hydrangeaceae. Wood vamp and climbing hydrangea are its common names. Its former name is Decumaria barbara. In the wild, it grows in swamps, bottomlands, and moist woods. It sheds its leaves, though some may stay on.

The vine climbs by small roots that grip its support. Garden sources give heights of 12–39 feet [3.7–12 metres]. One account records plants reaching 40 feet [12.2 metres]. Reported widths range from 1–8 feet [0.3–2.5 metres]. It grows at a moderate pace. Full size may take 10–20 years. Rough bark ranges from reddish brown to gray-brown. Slender twigs bear red, hairy buds. The glossy, dark green leaves grow in opposite pairs. Each leaf has a pointed tip and a smooth edge. Its underside is pale, and its fall color is tan.

Small white flowers form flat clusters at the stem tips. These fragrant blooms open in May and June. Many stamens give each cluster a soft, fluffy look. Bees, butterflies, and other insects visit the flowers. The vine flowers on new growth only when it climbs. Stems that trail across the ground do not bloom. Brown, ribbed capsules follow the flowers. They have an urn-like shape and split open when ripe. Fruit ripens from July through October.

Partial or dappled shade suits this plant well. Deep shade reduces its bloom, though the vine tolerates it. Some sources also allow sun, with shelter from cold winds. Rich, moist soil supports growth, and occasional flooding is tolerated. North Carolina guidance favors acid soil. RHS lists a wider pH range and prefers well-drained loam. USDA guidance places it in zones 6–8; RHS rates it H4. It can cover walls, fences, trellises, or arbors. Dense leaves also provide screening. Ground cover is another use, but gives no flowers.

Care needs are low, and major problems are uncommon. Aphids, mites, scale, capsid bugs, and vine weevils may occur. Leaf spots, powdery mildew, and gray mold can affect it. Honey fungus is another reported risk. Deer cause less damage than on some other plants. Its high flammability limits use close to homes. RHS warns that handling it can cause skin allergy. It also warns that eating it harms dogs and cats.