Hydrangeas
A Complete Guide to Hydrangeas
Few shrubs can match the beauty and versatility of hydrangeas. Their lush foliage, long-lasting blooms and wide range of colors make them one of the most popular landscape plants for gardens of every style.
Hydrangeas pair beautifully with smaller-leaved shrubs like azaleas, Japanese hollies and fine-needled evergreens, while also complementing colorful perennials. Their blooms last for months and can even be dried to enjoy indoors after the growing season ends.
Whether you're planting your very first hydrangea or adding another variety to your collection, understanding the different types and how to care for them will help you enjoy bigger, healthier blooms year after year.
The Four Most Popular Types of Hydrangeas
Bigleaf Hydrangeas (Hydrangea macrophylla)
Bigleaf hydrangeas are the classic hydrangeas most people picture. They produce either large, globe-shaped flower clusters (Mophead) or delicate, lace-like blooms with tiny center flowers surrounded by showy outer petals (Lacecap).
Growing Conditions
Bigleaf hydrangeas thrive in:
- Partial shade
- Moist, well-drained soil
- Consistent watering
Morning sun with afternoon shade is ideal, especially during hot summers.
Flower Color: Why It Changes
One of the most fascinating features of bigleaf hydrangeas is that many varieties naturally change color depending on your soil's pH.
For blue flowers:
- Soil pH: 4.5–5.5
- Use Espoma Organic Soil Acidifier to lower soil pH.
For pink or red flowers:
- Soil pH: 6.5–7.5
- Apply Espoma Organic Garden Lime to raise soil pH.
White varieties generally remain white regardless of soil conditions. A little afternoon shade also helps preserve richer flower color throughout the summer.
Blooming Habits
Older varieties bloom only on old wood, meaning they produce flower buds during late summer and fall for the following year's blooms. If these plants are heavily pruned in fall or early spring, or if winter cold damages the buds, flowering may be greatly reduced.
Many newer reblooming varieties bloom on both old wood and new wood. Even if winter damages the older stems, these plants can still produce flowers on new growth, resulting in a longer bloom season and more reliable flowering.
Watering
Bigleaf hydrangeas have shallow, fibrous root systems and are among the first landscape plants to wilt during dry weather.
Don't panic if you see drooping leaves on a hot afternoon, they often recover by evening! However, prolonged dryness can lead to scorched or burned leaf edges.
To keep plants healthy:
- Water deeply during dry spells.
- Apply mulch to help retain soil moisture.
- Avoid letting the soil dry out completely.
Pruning
Prune bigleaf hydrangeas immediately after flowering, only if needed to remove dead stems or shape the plant. Avoid heavy pruning in late fall or spring, especially on older varieties.
Oakleaf Hydrangeas (Hydrangea quercifolia)
Oakleaf hydrangeas offer beauty in every season. Their large white cone-shaped flowers gradually age to shades of pink before drying to tan, while their distinctive oak-shaped leaves develop spectacular shades of burgundy, crimson and deep red in autumn.
Growing Conditions
Oakleaf hydrangeas grow well in:
- Full sun to partial shade
- Moist, well-drained soil
They tolerate more shade than many flowering shrubs, although blooming may be reduced in heavier shade.
Size
Depending on the variety, oakleaf hydrangeas can mature anywhere from:
- 3–4 feet tall
- Up to 12 feet tall and wide
Be sure to choose a location that allows plenty of room for larger varieties to mature.
Pruning
Oakleaf hydrangeas bloom on old wood, so prune only after flowering if shaping is necessary.
Smooth Hydrangeas (Hydrangea arborescens)
Smooth hydrangeas are known for their huge flower heads and dependable flowering. They make excellent specimen plants, foundation plantings or flowering hedges.
Growing Conditions
Smooth hydrangeas perform well in:
- Full sun to partial sun
- Moist, fertile soil
Most varieties grow approximately 3–5 feet tall.
Pruning
Unlike bigleaf and oakleaf hydrangeas, smooth hydrangeas bloom on new wood. For the best flowers each year, cut plants back to the ground in early spring before new growth begins.
Because the flower heads can become extremely large, stems may occasionally bend or flop after heavy rain.
Panicle (P.G.) Hydrangeas (Hydrangea paniculata)
Panicle hydrangeas, often called P.G. hydrangeas, are among the easiest hydrangeas to grow. They are extremely cold hardy, tolerate more sun than most other types and produce enormous cone-shaped blooms from midsummer into fall.
Growing Conditions
Panicle hydrangeas thrive in:
- Full sun to partial sun
- Well-drained soil
They're excellent choices for:
- Foundation plantings
- Shrub borders
- Privacy screens
- Accent plantings
Many varieties grow between 3–8 feet tall depending on the cultivar.
Panicle hydrangeas are also available in attractive tree forms, making excellent small ornamental trees with spectacular summer blooms.
Pruning
Panicle hydrangeas bloom on new wood, so prune them in early spring before new growth begins.
Quick Hydrangea Care Guide
| Hydrangea Type | Sun | Blooms On | Best Time to Prune |
|---|---|---|---|
| Bigleaf | Partial shade | Old wood (newer varieties also bloom on new wood) | Right after flowering |
| Oakleaf | Full sun to partial shade | Old wood | Right after flowering |
| Smooth | Full sun to part sun | New wood | Early spring |
| Panicle (P.G.) | Full sun to part sun | New wood | Early spring |
Enjoy Beautiful Hydrangeas for Years to Come
With so many varieties to choose from, there's a hydrangea for nearly every landscape. The key to success is simply knowing which type you're growing, giving it the right amount of sunlight and water and pruning at the proper time.
Once established, hydrangeas reward gardeners with months of spectacular blooms, stunning color and beauty that never goes out of style.