Hydrangea macrophylla 'Penny Mac'
A vigorous mophead that often reblooms and stays reliable in warm, humid regions.
It can flower on both last year’s wood and new shoots.
Color shifts from pink to blue with soil pH and aluminum availability.
Best in partial shade and moist, fertile, well‑drained soil.
At‑a‑glance
- Group/Class: Bigleaf hydrangea, Mophead
- Height × spread: 4–6 ft (1.2–1.8 m) × 3–5 ft (0.9–1.5 m)
- Bloom window: early summer with repeats into fall
- Color & flower form: pink to blue mopheads
- Fragrance: 0 none
- USDA hardiness: zones 5–9
- Breeder / Year / Origin: Penny McHenry, year unknown, USA
- Awards/registration: Louisiana Super Plant, 2012
- Cut‑flower notes: usable stems; conditioning essential; wilt‑prone if stems dry
- Pet safety: avoid
How it differs
- More likely to rebloom than many older mopheads.
- Stays reliable in Southeast heat and humidity.
- Taller than compact modern selections.
Strengths
- Dependable summer color
- Rebloom potential
- Large, showy heads
Care in one minute
- Light: morning sun, afternoon shade.
- Soil: rich, well drained; acidify for blue where desired.
- Water weekly; mulch 2–3 in (5–8 cm).
- Deadhead; prune only dead or weak wood right after bloom.
Watch‑outs
- Late frosts can reduce early bloom in cold zones
- Needs steady moisture
- High pH soils may cause chlorosis
Best uses (tags)
- borders
- shade‑tolerant
- cutting
Provenance note
Named for Penny McHenry, founder of the American Hydrangea Society. Introduced to commerce from her garden selections and later trialed by universities.
References
Missouri Botanical Garden – ‘Penny Mac’
LSU AgCenter — Penny Mac named Louisiana Super Plant (2012)
NC State Extension — Hydrangea macrophylla species
ASPCA — Hydrangea toxicity
Written by: Your Flowers Guide editorial team
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