Hydrangea macrophylla 'Endless Summer'
A reblooming bigleaf hydrangea that flowers on last year’s wood and again on new growth.
Its standout trait is dependable rebloom after deadheading or winter dieback.
Color shifts from pink to blue with soil acidity and available aluminum.
Best in morning sun, afternoon shade, and evenly moist, well‑drained, organic soil.
At‑a‑glance
- Group/Class: Bigleaf hydrangea, Mophead
- Height × spread: 3–5 ft (0.9–1.5 m) × 3–5 ft (0.9–1.5 m)
- Bloom window: early summer to fall; reblooming
- Color & flower form: pink to blue mophead clusters
- Fragrance: 0 none
- USDA hardiness: zones 4–9
- Breeder / Year / Origin: Vernon G. Black, 2004, USA
- Awards/registration: S. Plant Patent PP15,298; cultivar ‘Bailmer’
- Cut‑flower notes: medium stems; conditioning essential; wilt‑prone if stems dry
- Pet safety: avoid
How it differs
- Reblooms on old and new wood.
- More cold tolerant than many bigleaf types.
- Patent notes better mildew tolerance than ‘Nikko Blue’.
Strengths
- Long season with deadheading
- Large, showy heads
- Performs in containers and borders
Care in one minute
- Site: morning sun, afternoon shade; shelter from wind.
- Soil: rich, well drained; pH 5.2 to 5.8 for blue tones.
- Water weekly; maintain 2–3 in (5–8 cm) mulch.
- Feed lightly in spring; avoid hard pruning; deadhead after bloom.
Watch‑outs
- Needs steady moisture; mulch helps
- Leaves scorch in hot afternoon sun
- Blue color needs acidic soil with aluminum
Best uses (tags)
- cutting
- borders
- containers
- shade‑tolerant
Provenance note
Cultivar ‘Bailmer’ discovered in Minnesota and patented in 2004. Marketed as Endless Summer The Original.
References
- U.S. Plant Patent: ‘Bailmer’ PP15,298
- Missouri Botanical Garden — Hydrangea macrophylla ‘Bailmer’
- ASPCA — Hydrangea toxicity
Written by: Your Flowers Guide editorial team
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