Bigleaf hydrangea Hydrangea macrophylla
Bigleaf hydrangea (Hydrangea macrophylla) is a deciduous perennial shrub in the Hydrangeaceae family. It grows 1–2 m (3.3–6.6 ft) tall and 1–2 m (3.3–6.6 ft) wide, wants part sun to part shade and high water, and is hardy to about -20 °C (-4 °F). Space plants about 1.5 m (4.9 ft) apart.
Plan Bigleaf hydrangea in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Bigleaf hydrangea at a glance
| Type | Perennial shrub, deciduous |
|---|---|
| Family | Hydrangeaceae |
| Mature height | 1–2 m (3.3–6.6 ft) |
| Mature spread | 1–2 m (3.3–6.6 ft) |
| Spacing | 1.5 m (4.9 ft) centre to centre |
| Sun | Part sun to part shade, at least 4 h of direct sun a day |
| Water | High; drought tolerance none, waterlogging tolerance low |
| Cold hardiness | About -20 °C (-4 °F) once established (roughly USDA zone 6) |
| Heat stress | Likely above about 32 °C (90 °F) |
| Flowering | from about June for 9–14 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | None |
| Pollinator value | Low |
| Edible | Not grown as food |
| Common in gardens of | 🇯🇵 Japan, 🇨🇳 China, 🇺🇸 United States, 🇬🇧 United Kingdom, 🇫🇷 France, 🇩🇪 Germany, 🇵🇹 Portugal, 🇦🇷 Argentina, 🇨🇱 Chile, 🇳🇱 Netherlands, 🇮🇪 Ireland, 🇳🇿 New Zealand |
Is Bigleaf hydrangea toxic?
- People: mildly toxic
- Cats: moderately toxic
- Dogs: moderately toxic
- Parts: leaves, buds, flowers
Cyanogenic glycosides can cause vomiting and lethargy if eaten.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Bigleaf hydrangea
No well-documented helpful pairing. Group it with plants that like part sun to part shade and high water.
See Bigleaf hydrangea in a botanical garden
It grows in this sample garden, which you can walk through in 3D:
- Longwood Gardens (8 plants)
Questions about Bigleaf hydrangea
- How far apart should I plant Bigleaf hydrangea?
- About 1.5 m (4.9 ft) apart, centre to centre. A mature plant spreads 1–2 m (3.3–6.6 ft).
- Does Bigleaf hydrangea need full sun?
- Part sun to part shade: at least 4 hours of direct sun a day.
- How much water does Bigleaf hydrangea need?
- High water. Drought tolerance is none and waterlogging tolerance low.
- How cold-hardy is Bigleaf hydrangea?
- It tolerates about -20 °C (-4 °F) once established, roughly USDA zone 6.
- When does Bigleaf hydrangea flower?
- From about June for 9–14 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Bigleaf hydrangea poisonous to cats and dogs?
- For cats it is moderately toxic; for dogs moderately toxic; for people mildly toxic. Cyanogenic glycosides can cause vomiting and lethargy if eaten.
- What grows well with Bigleaf hydrangea?
- There is no well-documented companion pairing for Bigleaf hydrangea. Group it with plants that like the same sun (part sun to part shade) and water (high).
Sources and evidence
Evidence grade C (C: plausible, mixed evidence).
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
- FAO Irrigation and Drainage Paper 56 — Crop Evapotranspiration, FAO
- RHS Plant Finder, Royal Horticultural Society
- University extension gardening guides (general), Various land-grant university extensions
Notes and assumptions
- Typical garden-cultivar values; varieties differ.
- Flower colour depends on soil pH.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Mock orange Philadelphus coronarius
- Panicle hydrangea Hydrangea paniculata
- Smooth hydrangea 'Annabelle' Hydrangea arborescens
- Climbing hydrangea Hydrangea anomala subsp. petiolaris
- Slender deutzia (himeutsugi) Deutzia gracilis
- Mountain hydrangea (yama-ajisai) Hydrangea serrata
- Yellow wax bells (kirenga-shōma) Kirengeshoma palmata
- Rough-leaved hydrangea Hydrangea aspera