Hydrangea bloom profusely in spring and early summer, producing clumps of small flowers in a variety of pastel colors. The perennial shrubs are insect- and disease-resistant, require little more than yearly pruning and are tolerant of both sunny and partially shaded locations. Evenly moist soil throughout the growing season is the most vital element for successful hydrangea growing. Preparing the soil prior to planting and then practicing proper soil care ensures that the soil retains both the needed moisture and nutrients.
Break up the soil prior to planting with a tiller. Loosen it down to an 8-inch depth and over an area that is 3 to 4 feet larger in diameter than the hydrangea trunk.
Lay a 3 inch layer of organic material over the planting area then till it in to the 8 inch depth. Use fully decomposed compost, pine bark chips or shredded leaves. These materials add nutrients to the soil and also aid in retaining moisture without becoming soggy.
Apply a general-purpose, slow-release fertilizer over the planting area. Follow the application rate recommended on the fertilizer package, as this differs among fertilizers.
Fertilize the hydrangea every March when it begins producing new growth. Apply a slow-release, balanced fertilizer around the drip line of the hydrangea---the area at the edge of the hydrangea's canopy. Follow package application rates.
Apply a fresh 2-inch layer of compost mulch under the hydrangea after each spring fertilization. Spread the mulch out to the drip line. As the compost breaks down over the summer, it adds nutrients back into the soil.