The large and colorful blooms of a hydrangea (Hydrangea spp.) grace the gardens of homes in U.S. Department of Agriculture hardiness zones 5 through 9. If properly maintained, these shrubs can grow between 4 and 12 feet tall, and live for decades, sharing their frothy blooms most of the summer.
Hydrangeas are long-lived shrubs, sometimes living for up to 50 years if properly cared for. They enjoy morning sun but afternoon shade, and they need frequent watering during the growing season. Prune them in the fall after the blooms fade so they can grow on strong stems the following summer. Pruning the plants while they’re blooming can damage them, causing the hydrangeas to go a year without blooms while the plants recover.
Bigleaf hydrangeas also are called the common hydrangeas, and they bloom in several colors, including blue, pink and purple. These hydrangeas bloom earlier than some other varieties, often with blooms forming in May. The plants typically continue to develop blooms into July. Bigleaf hydrangeas are known to change bloom colors based on the soil properties; a plant that blooms pink one year can bloom blue the next. Adding aluminum sulfate to the soil encourages blue flowers, while adding hydrated lime brings pink blooms, which appear in alkaline soils. Cultivars include “Ayesha,” “Nikko Blue” and “Preziosa.”
The smooth hydrangea (Hydrangea arborescens) blooms longer than other hydrangeas, often showing color from early June through September. Cultivars include the white “Anabelle” and pink “Invincibelle Spirit.” Unlike other hydrangeas that bloom best on old wood, smooth hydrangeas usually bloom on the current year’s wood, which means you should prune them severely. Cut them down to within 6 to 12 inches of ground level.
Panicle hydrangeas (Hydrangea paniculata) get a later start in their blooming season, preferring to bloom in the heat of summer rather than the cool weather in spring. Often not getting started until July, panicle hydrangeas bloom into September. Their flowers start out as white and begin to change to a rusty pink as fall draws near.
Hydrangeas can develop large blooms in their first year, but if you move the plants or transplant one from a pot to the ground, the hydrangeas might skip blooming for a year or even two. This doesn’t mean they are finished blooming for life. Continue watering regularly, and fertilizing the plants in the spring, summer and fall with a balanced fertilizer, and blooms should start developing once their roots get over the shock of transplantation.
Based outside Atlanta, Ga., Shala Munroe has been writing and copy editing since 1995. Beginning her career at newspapers such as the “Marietta Daily Journal” and the “Atlanta Business Chronicle,” she most recently worked in communications and management for several nonprofit organizations before purchasing a flower shop in 2006. She earned a BA in communications from Jacksonville State University.