Things You'll Need
Merritt's Supreme hydrangea, a variety of Hydrangea macrophylla, is a compact shrub that grows to a height of only 4 feet, making it ideal for small gardens. Merritt's Supreme blooms in pink flowers, unless the soil is acidic, in which case the flowers will be blue. Merritt's Supreme hydrangeas grow well in U.S. Department of Agriculture plant hardiness zones 6 through 9.
Water Merritt's Supreme hydrangea when the top 2 inches of soil is dry. In the summer, if the weather is warm and dry, check the shrub and the soil more frequently as it will dry out faster. If the shrub appears to be wilting, water it.
Apply a 3-inch layer of rotted manure, spreading it on the soil beneath the shrub from the trunk to the dripline, in summer. Water the shrub after application of the manure.
Add a 3-inch layer of mulch to the soil around the hydrangea, 6 inches from the plant. Mulch helps conserve moisture in the soil in summer and insulates the plant's roots in winter. In the spring, rake back the mulch and dispose of it. Place a 3-inch layer of compost on the soil around the shrub and cover that with a fresh, 3-inch layer of mulch.
Prune the hydrangea after flowering is complete. The plant seldom requires heavy pruning, but you must remove any dead branches and those crossing others. If you live in an area of high humidity, prune some of the growth from the middle of the plant to allow better air circulation.