Height: 1.2 m (4 feet)
Spread: 1.0 m (3 feet)
Bloom: Large pink or blue mopheads
Exposure: Full sun to part shade, prefers part shade
Foliage: Large medium green
Pluses: long bloom period, large flowers
Endless Summer Hydrangea is a repeat blooming hydrangea that blooms on both old and new growth. It’s large mop-head type blooms can be pink (in alkaline soil) or blue (in acidic soil). Endless Summer Hydrangea are drought tolerant but with a caveat. I have plants in several gardens, some in full sun until the overhead trees grow larger, some in part shade. Those in full sun require an additional watering during hot, dry weather, to look their best although established plants will survive drought even without watering. Without watering the leaves droop and look quite sickly but will quickly perk back up with cooler weather or water.
In my zone 5 Southern Ontario garden, blooms start towards the middle of June (assuming the first blooms were not damaged by frost) and with deadheading will re-bloom until frost. To keep a constant bloom of colour you need a good mix of new inflorescence and old.
In northern climate gardening, Endless Summer needs to be protected from frost in early spring. Even though it is very hardy I think our typical late spring frosts damage the blossom growth by setting the plant back too severely. This means that many years blooms are delayed and few. I am going to experiment with mulching the bottom foot or so of my Endless Summer hydrangea in late fall (after the leaves have dropped) and leaving them protected until the chance of spring frost is well past. Endless Summer also seems to prefer a bit of tough love, no fertilizing or watering.
Garden Locations: Kitchen Patio Garden, Front Entrance Garden, Front Walkway and Pool Gardens. The oldest plants (in the Front Entrance Gardens) are now 6 years old and grow 3 feet each year. Plants in less rich soil in other gardens grow about 2 feet.