When Are Hydrangeas in Season in the Northeast US?

Considerations

• The Northeast United States has a wide range of temperate hardiness zones. From northern Maine, with its spots of U.S. Department of Agriculture plant hardiness zone 3b to USDA zone 7 on Cape Cod and Nantucket, the northeast is a collection of strips of climate thanks to the warm ocean currents on the east and mountains on the west. When you add the variability of the different species of hydrangeas, there’s likely to be a hydrangea blooming in the northeast over a long growing period. Cape Cod plants might bloom two to three weeks ahead of those in inland areas, depending on last average frost dates, which can range from late April on the coast to early June inland.

Early Season

• The earliest-blooming hydrangea is the climbing vine (Hydrangea anomala subsp. petiolaris), hardy from USDA zone 4 to zone 8. It blooms from May to July across the Northeast, except in the coldest areas in ranges of the Appalachian Mountains. Vines bear fragrant white lacecap flowers. Some bear starlike blooms. Vines grow from 30 to 50 feet tall. Southeastern native oakleaf hydrangea (Hydrangea quercifolia) is hardy from USDA zone 5 through zone 9 and grows in a 6- to 8-foot round shrub. Pyramidal panicles of white flowers bloom from May through July. Flowers mature to a pinkish lavender. Oakleaf hydrangea is named for its unusual leaves, which turn shades of bronze, red and purple in fall.

Mid-Season

• Eastern native Annabelle (Hydrangea arborescens), hardy from USDA zone 3 to zone 9, grows as a shrub, 3 to 5 feet in height and diameter, that spreads by suckering. It produces spectacular white balls of flowers and recent hybrids introduce flowers with green and blue highlights. Bloom begins in June and extends through September. Cape Cod’s venerable and varied mopheads (Hydrangea macrophylla), hardy from USDA zone 5 through zone 11, begin their bloom in late June or early July. They bloom as lacecaps or large flowered globes in shades of blue, lavender, pink and white. Some lacecap mopheads feature one color in the sterile center buds and another in the surrounding flowers.

Late Season

• Many hydrangeas are in bloom or maturing in July, making it the height of the hydrangea season. Panicle hydrangea (Hydrangea paniculata), hardy from USDA zone 3 to zone 8, grows 8 to 15 feet tall and spreads up to 12 feet. It blooms from July through September in panicles of white, although some cultivars progress through shades of green or pink as they mature. Hydrangea flowers persist, fading to tan or brown from late August through September.