Climbing hydrangea can reach lengths of 80 feet with branching stems extending outward up to 3 feet. The hydrangea vine produces clusters of small, fragrant white florets (tiny flowers) for four to six weeks starting in early summer. Climbing hydrangea uses aerial rootlets, root-like attachments, to cling to a support. Fully grown, the hydrangea vine will be heavy and requires a sturdy support, like a pergola or brick wall. Climbing hydrangea is cold hardy in U.S. Department of Agriculture zones 4 to 7 and should be planted in early spring.
Look at the landscape for the best location of a climbing hydrangea. The location should be well-drained and in full sun to part shade with morning sun and afternoon shade preferred. The vine may produce fewer or smaller blooms in part shade. The location should be next to a support mechanism, like a pergola or a wall or chimney made with bricks.
Dig the hole about 6 inches from the support. The hole should be two to three times as wide as the root ball and as deep as the root ball is tall. If planting in clay soil, dig the hole twice as deep as the root ball and mix about 30 percent organic matter, like compost or leaf mold, in with the soil that is returned to the bottom of the hole. The loosened soil helps root penetration.
Remove the climbing hydrangea from the container and place the root ball in the center of the hole. The top of the root ball should be at ground level. Add or remove soil from the bottom of the hole if necessary.
Backfill around the root ball with the soil removed the hole. Water around the root ball to settle the soil and then add more soil if needed to level out the area.
Apply 2 to 3 inches of mulch, like wood chips, over the worked area. Keep the mulch about 3 inches away from the stem. Mulch will help to block weed growth and help to retain moisture.
Water regularly during the first growing season, spring to fall. Water every seven to 10 days if there is no rainfall. In subsequent years, watering is only needed during extended dry conditions and when the soil around the plant is dry 4 inches down.