Gardeners love hydrangeas for their giant blossoms, which add vibrant color to any shaded garden, according to the University of Rhode Island. Though Ohio State University reports that hydrangeas are very easy to grow, several management strategies and tips can help maximize your hydrangea plant's health and ensure optimal growth for a showy profusion of lush foliage and bright flowers.
Spread 3 to 4 inches of mulch around the base of the hydrangeas and work 2 inches of compost into the surrounding soil. This helps conserve soil moisture and increases the dirt's concentration of organic matter to mimic the moist woodland soil that the plants thrive on in the wild, according to Ohio State University.
Water the hydrangeas. The University of Rhode Island suggests a once-a-week irrigation schedule for plants grown directly in the ground, applying enough water so that the soil is moist to a depth of 6 to 8 inches. Potted plants may need watering every three to four days, depending on the pot size. Observe the hydrangea plant for signs of drought stress--symptoms include the yellowing or wilting of foliage--since water needs may be greater or lower depending on your climate and soil type.
Feed the hydrangea plants to encourage continuous foliage growth and blossom production. Plants in the ground need fertilization once a year in the early spring with a complete fertilizer like a 5-10-10 product, spread at a rate of 1 lb. for every 50 square feet, according to the University of Rhode Island. Potted hydrangeas thrive with a weekly fertilizer formulated for houseplants, according to Texas A&M University.
Deadhead the hydrangea plant to boost the plant's flower growth. After the flowers have wilted, cut off the flower stem and discard it.
Eradicate pests. Ohio State University says hydrangeas are susceptible to fungal disease problems like powdery mildew, as well as insect pests like aphids and spider mites. A basic plant fungicide formulated with fixed copper can destroy fungal spores, while a standard insecticidal soap will kill most insect pests. Obtain fungicides and pesticides from garden stores and nurseries.