Hydrangea
Hydrangea macrophylla
📖 About this plant
One of the most beloved flowering shrubs, hydrangeas produce massive, showy flower clusters in shades of blue, pink, purple, white, and green. Bigleaf (macrophylla) hydrangeas are famous for their color-changing ability based on soil pH. Other popular types include panicle (cone-shaped white-to-pink blooms), smooth (mophead on native species), and oakleaf hydrangeas. They provide spectacular summer and fall color.
🧑🌾 Care requirements
Partial shade to morning sun (4-6 hrs)
Every 2-3 days
Moderate to high (50-70%)
10-25°C
Moisture-retentive, well-draining loam rich in organic matter; pH 5.0-5.5 for blue flowers, pH 6.0-6.5 for pink flowers. Aluminum availability affects flower color in macrophylla types
Acid-loving plant fertilizer (sulfur or aluminum sulfate for blue flowers; lime and phosphorus for pink); apply balanced fertilizer in spring and mid-summer; avoid late-season feeding which prevents winter hardiness
🌐 Common Names
📋 Plant facts
- 🌍 Origin
- Japan, eastern Asia (macrophylla); North America (arborescens, paniculata)
- 📏 Max height
- 90-300 cm depending on species and variety
- 📐 Spread
- 120-180 cm
- 🕰️ Bloom time
- Summer - Fall
- 🎨 Bloom color
- Blue, Pink, White
- 🍃 Foliage color
- Green
- ⏳ Lifespan
- Perennial
- 📈 Growth rate
- Moderate
- ☠️ Toxicity
- Toxic — all parts contain cyanogenic glycosides (especially buds and leaves) which release hydrogen cyanide when ingested, causing nausea, vomiting, dizziness, and in severe cases respiratory distress. Toxic to dogs, cats, and horses
- 🌱 Propagation
- Take softwood cuttings in late spring (4-6 weeks to root under mist); layer low branches in spring; divide in early spring; some species can be propagated from seed
🛡️ Health & Safety
Toxic — all parts contain cyanogenic glycosides (especially buds and leaves) which release hydrogen cyanide when ingested, causing nausea, vomiting, dizziness, and in severe cases respiratory distress. Toxic to dogs, cats, and horses
Common issues
- Wilting in afternoon heat even when soil is moist
- Bud damage from late spring frosts (especially macrophylla)
- Powdery mildew in humid conditions
- Failure to bloom from improper pruning of old wood types
💡 Care tips
- Soil pH determines flower color: acidic for blue alkaline for pink
- Prune after flowering for species that bloom on old wood
- Water deeply at the base rather than shallow sprinkling
- Mulch thickly to retain moisture in summer
