The Best Time of Year to Transplant Climbing Hydrangea

About Climbing Hydrangea

• Climbing hydrangea is slow to settle in, but once established it quickly reaches 50 feet or more; without something to climb, it forms a 3- to 4-foot shrub. This woody vine climbs by twining and with aerial rootlets. Side branches give the vine a three-dimensional aspect. Climbing hydrangeas are hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9.

Transplanting Considerations

• Climbing hydrangea is slow to establish and shows little top growth for the first year or two, because it puts all its energy into establishing the root system. Climbing hydrangea needs careful attention for the first few years if the vine is to succeed. It is especially susceptible to harsh weather during the first winter after planting.

Transplanting Tips

• Give your climbing hydrangea the best possible chance for success by choosing and preparing the planting site carefully. Plant these vines in full sun or partial shade; a sheltered eastern or northern exposure is best. Prepare the planting hole 18 inches deep and 36 inches wide, and add compost or peat moss to the soil. Plant the vine so that the top of the root ball is at the same soil level as it was in the container, then backfill around the roots with the amended soil. Water well and spread a 2- to 3-inch layer of mulch over the roots. Water often enough that the roots stay moist but not soggy, and feed the plant regularly with an all-purpose fertilizer. Give both new and established climbing hydrangeas a deep watering before the ground freezes in the fall.

Moving an Established Plant

• Established climbing hydrangeas are large, very heavy and difficult to move successfully. If you must transplant an existing plant, do so only in the spring and enlist some helpers. Water the plant well the day before digging, then prune the top of the plant back to 2 to 3 feet above the soil line. Dig as large a root ball as possible and slide burlap or a tarp underneath it to keep the soil and roots intact. Move the plant to its new location and place it in a prepared planting hole so that the root ball is at the same level as it was before. Backfill around it, then care for the plant as you would a new specimen. It may take several years for the vine to recover.

The Bottom Line

• Avoid planting climbing hydrangea during the summer, as the heat and humidity will stress the plant and prevent it from making good root growth. Throughout its range, the best time to plant the vine is in the spring so that it has a whole growing season for the roots to establish. However, in USDA zones 8 and 9, you can plant climbing hydrangea in early September, which will give the roots three or four months of active growth before cold weather arrives. If you do plant the vine in the fall, place an airy winter mulch of straw or loose leaves over the crown of the plant for extra protection during its first winter.