Oakleaf hydrangea, scientific name “Hydrangea quercifolia,” can reach 10 feet tall and 8 feet wide. In early summer, oakleaf hydrangea produces white, cone-shaped blooms that fade to pink and then tan. The leaves of this deciduous shrub are shaped like those of an oak tree and can reach 12 inches across. In autumn the leaves of oakleaf hydrangea turn red before falling off. Oakleaf hydrangea is cold hardy in USDA zones 5B through 9. Plant oakleaf hydrangea in the spring in zones 5B through 6, and any time of the year in zones 7 through 9.
Choose a well-drained location in full sun or dappled shade. Unlike other hydrangea varieties, oakleaf is not particular about the pH balance of the soil. Allowing the oakleaf hydrangea to grow naturally without annual pruning will require an open area of about 8 feet in diameter.
Dig the hole 2 feet wider than the root ball and as deep as the root ball is tall.
Mix is about 20 percent organic matter, like compost of leaf mold, if desired. Adding organic matter to clay soil can help root penetration.
Remove the oakleaf hydrangea from the container. Use your fingertips to loosen the roots on the lower portion root ball.
Place the root ball in the center of the hole. The top of the soil of the root ball should be level with the surrounding ground. Adjust the soil level in the bottom of the hole if necessary.
Backfill the hole and then water to settle the soil. Add more soil to the hole if needed and then water again.
Apply 2 to 3 inches of mulch, like bark chips, over the root ball. Keep the mulch about 4 inches from the stem of the shrub. Mulch will help retain moisture and block weed development.
Water every seven to 10 days, spring to early fall, if there is no rainfall.