Endless Summer hydrangea is a cultivar of the popular garden plant valued for its abundant, long-lasting flowers that bloom on new and old wood alike. Endless Summer hydrangea is hardy in zones 4 through 9, making it viable for gardeners in most areas of the United States. The plant can reach up to 5 feet tall in the home garden and requires little care to thrive. Selecting an appropriate planting location is perhaps the most important part of Endless Summer hydrangea care.
Plant Endless Summer hydrangea during spring or summer. Choose an area of the garden that has fertile, well-drained soil and receives morning sun and afternoon shade or partial shade throughout the day. In zones 4 and 5, allow six hours of direct sunlight with a few hours of partial shade in the afternoon.
Apply water to Endless Summer hydrangea two to three times per week. Soak the soil thoroughly at each application to keep the soil consistently moist, but not wet. Increase watering to four times per week if the plant's leaves begin to droop during high temperatures.
Mulch the soil surrounding Endless Summer hydrangea using a thick, organic mulch such as shredded bark or pine needles. Apply a 2- to 3-inch layer of mulch to the soil, beginning at least 3 inches from the base of the plant to allow adequate air circulation. Refresh the mulch as necessary throughout the year.
Feed Endless Summer hydrangea once per year in late spring or early summer. Use a fertilizer with low nitrogen and high phosphorus such as 10-30-10 NPK or 10-40-10 NPK for the best results. Apply according to the manufacturer's directions for proper dosage. Do not fertilize in fall and winter.
Remove spent flowers from Endless Summer hydrangea plants as soon as possible to encourage new blossoms. Use pruning shears to remove dead or damaged branches after blooming, but do not cut back to the ground, since Endless Summer hydrangeas bloom on new and old wood.