A reblooming hydrangea is a cultivar that blooms on both old woody stems and fresh new growth, extending the blooming season into summertime. Some of the most popular reblooming hydrangea cultivars include ‘Endless Summer,’ ‘Summer Crush,’ ‘Bloomstruck,’ ‘Blushing Bride,’ ‘Tuff Stuff,’ and ‘Penny Mac.’ Most are cultivars of bigleaf hydrangea, with the odd reblooming mountain hydrangea also available.
Reblooming hydrangea basics
Unlike most hydrangeas, reblooming hydrangea cultivars produce flowers on both old and new wood. This extends their blooming season from spring through to summer. And since the blooms are so long-lasting on these plants, they can last into fall and even overwinter on the plant.
Most reblooming hydrangeas are bigleaf hydrangeas (Hydrangea macrophylla), but there are also several reblooming cultivars of mountain hydrangea (Hydrangea serrata). Even a few hybrids between the species grow in adjacent climates. Mountain hydrangeas are the best pick if you need deer-resistant plants.
The technical description for reblooming hydrangeas is “remontant,” which means that they bloom more than once a season. Remontant hydrangeas were unavailable in garden centers until the 2000s but have since become commonplace. They are especially prized in cooler climates like Zones 5-6, where Hydrangea macrophylla may never flower, as cold winter temperatures usually kill the overwintering flower buds.
“Where remontant or reblooming types differ is that they have the firepower and precocity to produce flower fast, throwing out shoots that will flower at the top on fresh growth, without a winter break and whether or not they are cut to the ground.”
Hydrangeas: beautiful varieties for home and garden, by Naomi Slade
Climate considerations for reblooming hydrangeas
In their ideal climate of Zone 7, reblooming hydrangeas tend to bloom reliably from early summer (June) through until the fall (September-October). In these climates, remontant hydrangeas truly do bloom all summer. Trimming off spent flowers will encourage the plant to rebloom, so be sure to deadhead regularly in the summer.
At the cooler end of their growing range, Zones 4-6, overwintering flower buds are often killed by cold temperatures and desiccating winds. In these colder climates, reblooming hydrangeas often only get the second round of blooms. The overwintering buds don’t make it to springtime, so the plant’s only chance to bloom is on fresh new growth. This delays the start of the flowering season considerably.
At the hotter end of their growing range, Zones 8-9, the summer weather often gets so hot in mid-to-late summer that the plants stop blooming. Avoid direct sunlight in the afternoon in these climates and site the plants in a cool spot with ample water if possible.
Types of reblooming hydrangea
Most types of reblooming hydrangea are of the species Hydrangea macrophylla, the Bigleaf Hydrangea. That said, some cultivars are of the species Hydrangea serrata, also called the mountain hydrangea. A few newer cultivars have been cross-bred between these two species to produce particularly hardy reblooming hydrangeas.
Varieties of reblooming hydrangeas
Here are some popular lines of reblooming hydrangeas available in garden centers.
Endless Summer series
The Endless Summer line of reblooming hydrangeas includes:
- The Original Endless Summer Hydrangea (Hydrangea macrophylla ‘Bailmer’)
- Blushing Bride Hydrangea (Hydrangea macrophylla ‘Blushing Bride’)
- BloomStruck Hydrangea (Hydrangea macrophylla ‘PIIHM-II’)
- Summer Crush Hydrangea (Hydrangea macrophylla ‘Bailmacfive’)
- Twist-n-Shout Hydrangea (Hydrangea macrophylla ‘PIIHM-I’)
- Pop Star Hydrangea (Hydrangea macrophylla ‘Bailmacsix’)
Endless Summer hydrangeas are offered by Bailey Nurseries. The plants are usually found at the garden center in baby blue planter pots.
Let’s Dance series
The Let’s Dance line of reblooming hydrangeas includes:
- Rave Hydrangea (Hydrangea macrophylla ‘SMNHMSIGMA’)
- Blue Jangles Hydrangea (Hydrangea macrophylla ‘SMHMTAU’)
- Starlight Hydrangea (Hydrangea macrophylla ‘Lynn’)
- Rhythmic Blue Hydrangea (Hydrangea macrophylla ‘SMHMES14’)
- Diva! Hydrangea (Hydrangea macrophylla ‘SMHMLDD’)
- Big Easy Hydrangea (Hydrangea macrophylla ‘Berner’
- Big Band Hydrangea (Hydrangea macrophylla ‘SMNHMP’)
- Sky View Hydrangea (Hydrangea macrophylla × serrata ‘SMNHSME’)
- Can Do! Hydrangea (Hydrangea serrata ‘SMNHSI’)
- ¡Arriba! Hydrangea (Hydrangea x ‘SMNHSC’)
Let’s Dance hydrangeas are offered by Proven Winners. The plants are usually found at the garden center in white planter pots.
Seaside Serenade series
The Seaside Serenade line of hydrangeas includes the reblooming varieties:
- Newport Hydrangea (Hydrangea macrophylla ‘HORTMANI’)
- Hamptons Hydrangea (Hydrangea macrophylla ‘HORTHAMP’)
- Fire Island Hydrangea (Hydrangea macrophylla ‘HORTFIRE’)
- Glacier Bay Hydrangea (Hydrangea macrophylla ‘CAMCHO45’)
- Cape Cod Hydrangea (Hydrangea macrophylla ‘HMUPSI’)
- Cape Hatteras Hydrangea (Hydrangea macrophylla ‘HORTHAT’)
- Crystal Cove Hydrangea (Hydrangea macrophylla ‘CAMFRE29’)
- Cape Lookout Hydrangea (Hydrangea macrophylla ‘HORTMABLO’)
- Outer Banks Hydrangea (Hydrangea macrophylla ‘SMHMEPSILON’)
- Martha’s Vineyard Hydrangea (Hydrangea macrophylla ‘HORTMAVI’)
Seaside Serenade hydrangeas are offered by Monrovia. The plants are usually found at the garden center in dark green planter pots.
Tuff Stuff series
The Tuff Stuff line of reblooming mountain hydrangeas includes:
- Tuff Stuff Hydrangea (Hydrangea serrata ‘MAK20’)
- Tuff Stuff Red Hydrangea (Hydrangea serrata ‘SMNMAKTSR’)
- Tuff Stuff Ah-Ha Hydrangea (Hydrangea serrata ‘SMNHSDD’)
- Tiny Tuff Stuff Hydrangea (Hydrangea serrata ‘MAKD’)
Tuff Stuff hydrangeas are offered by Monrovia. The plants are usually found at the garden center in white planter pots.
Forever & Ever series
The Forever & Ever reblooming hydrangea series includes the following varieties:
- Together Hydrangea
- Early Sensation Hydrangea
- Red Sensation Hydrangea
- Peppermint Hydrangea
- White Ball Hydrangea
- White Out Hydrangea
- Blue Heaven Hydrangea
- Fantasia Hydrangea
- Pistachio Hydrangea
You & Me series
The You & Me series (sometimes written You&Me or YOUME™) includes the following reblooming hydrangeas
- Passion Hydrangea (Hydrangea macrophylla ‘Rie 4’)
- Romance Hydrangea (Hydrangea macrophylla ‘Rie 9’)
More varieties
Here are some additional popular reblooming varieties:
- David Ramsey Hydrangea
- Decatur Blue Hydrangea
- Penny Mac Hydrangea
- Mini Penny Hydrangea
- Oak Hill Hydrangea
Endless Summer: The first reblooming hydrangea
The original reblooming hydrangea cultivar is called ‘Endless Summer’. According to the Washington Post, it was discovered by chance in 1998 at Bailey Nurseries in St. Paul, Minnesota.
Horticulture professor Micheal Dirr (author of the wonderful book Manual of Woody Landscape Plants, among many others) was taking a tour of the nursery and spotted a row of Hydrangea macrophylla flowering in September in Minnesota. The row had been propagated by nursery employee Vern Black from cuttings he had noticed in the garden of seasonal employee Dennis Bostrom.
“The original plant had been found by nursery employee Vern Black growing in the garden of a neighbor, Dennis Bostrom. Bostrom, a retired teacher who works seasonally at the nursery, was happy to let Black take some cuttings.”
The Hydrangea That Keeps On Giving: Endless Summer, a hydrangea breakthrough, by Adrian Higgins, Washington Post, 2006
Dirr recognized the significance of a specimen that flowered on both old and new wood, and worked with Bailey Nurseries to introduce the plant as ‘Endless Summer’. Since then, additional varieties have been developed as part of the Endless Summer brand and by other plant brands and breeders.
