Bigleaf Hydrangea Care: Mophead and Lacecap Hydrangeas

Bigleaf hydrangeas (Hydrangea macrophylla) are the big blue and pink mopheads and the flatter lacecaps that most people picture when they hear “hydrangea.” They are easy to keep alive and frustratingly easy to keep from blooming. The reason is that most bigleaf hydrangeas form next summer’s flower buds on this year’s stems in late summer and fall, so anything that kills or removes those stems, whether a fall pruning, a hard winter or a late spring frost, costs you the flowers. Get three things right: morning sun with afternoon shade, steady moisture, and pruning only right after bloom, and these shrubs will flower reliably for decades.

Part of our Flowers & Perennials guide →

In this guide

1. Mophead, Lacecap and Nikko Blue
2. Where to Plant Bigleaf Hydrangeas
3. How to Plant
4. Watering and Feeding
5. Changing Flower Color: Blue or Pink
6. Pruning Bigleaf Hydrangeas
7. Winter Protection
8. Common Problems
9. Bigleaf Hydrangea Care Calendar
10. Bigleaf Hydrangeas in Containers
11. Frequently Asked Questions

Mophead, Lacecap and Nikko Blue

All of these are Hydrangea macrophylla; they differ in flower shape and bloom habit.

• Mophead (hortensia) hydrangeas have large, rounded heads made almost entirely of showy sterile florets. They are the classic cottage-garden hydrangea.
• Lacecap hydrangeas have a flat center of tiny fertile flowers ringed by larger showy florets. They look more natural, attract more pollinators and often hold up better in wind and rain.
• Nikko Blue is an older, popular mophead with rich blue flowers in acidic soil. Like most traditional varieties, it blooms only on old wood and is generally rated for zones 6 to 9.
• Reblooming varieties such as the Endless Summer series and many newer introductions bloom on both old and new wood, so they can still flower after a hard winter kills last year’s buds. These are the best choice in zone 5 and colder parts of zone 6.

Not sure which hydrangea you have? Bigleaf types have thick, glossy, coarsely toothed leaves and flowers that change color with soil pH. If your plant has cone-shaped white flowers, it is a panicle hydrangea; see our panicle hydrangea care guide, which follows very different pruning rules. Our broader hydrangea care guide compares every type.

Where to Plant Bigleaf Hydrangeas

Light

Morning sun and afternoon shade is the ideal combination almost everywhere. In the South and in hot inland areas, afternoon shade is essential; plants in full afternoon sun wilt daily and scorch. In the cool North and on the coasts, bigleaf hydrangeas can take more sun, which improves flowering. Deep shade produces healthy leaves but few flowers. Our guide to hydrangeas for sun and shade covers siting by region.

Soil

Rich, moist, well-drained soil with plenty of organic matter. Mix compost into the planting area, especially in sandy or clay soil. Avoid low spots where water sits after rain, and avoid planting right against a foundation where lime from concrete can raise soil pH and turn blue flowers pink.

Shelter

In zone 6 and colder, an east-facing spot sheltered from winter wind improves bud survival. Avoid frost pockets at the bottom of slopes, where cold air settles on spring nights and kills tender new growth.

Spacing

Most bigleaf hydrangeas grow 3 to 6 feet tall and wide. Check the tag; compact varieties stay around 3 feet, while older types like Nikko Blue can reach 6 feet. Space plants at roughly their mature width so you never have to prune for size, which is the most common cause of lost blooms.

How to Plant

1. Plant in spring after frost danger or in early fall, at least six weeks before the ground freezes.
2. Dig a hole two to three times as wide as the root ball and no deeper.
3. Set the plant so the top of the root ball is level with or slightly above the surrounding soil.
4. Backfill with native soil mixed with some compost, firm gently, and water deeply.
5. Mulch 2 to 3 inches deep with shredded bark or leaves, keeping mulch a few inches off the stems.

Watering and Feeding

The “hydra” in hydrangea refers to water, and bigleaf types are thirsty. Give them about an inch of water a week, more during heat and in the first two seasons after planting. Water deeply at the base two or three times a week rather than a little daily. Some afternoon wilting on hot days is normal; if leaves are still limp the next morning, the plant needs water. Mulch helps keep roots cool and moist.

Feed lightly. A slow-release shrub fertilizer or a few inches of compost in spring as leaves emerge is usually enough, applied at the label rate. Too much nitrogen produces lush leaves and fewer flowers. Do not fertilize after midsummer; late feeding encourages soft growth that is more easily damaged by early frosts.

Changing Flower Color: Blue or Pink

In pink and blue bigleaf hydrangeas, flower color depends on whether the plant can take up aluminum from the soil, which depends mainly on pH. White varieties stay white regardless.

Soil pH	Typical color	How to get there
About 5.0 – 5.5	Blue	Apply aluminum sulfate or sulfur per label; mulch with pine bark or needles
About 5.5 – 6.0	Purple or mixed	Often the natural result in mildly acidic soil
About 6.0 – 6.5 and up	Pink	Apply garden lime per label; use a higher-phosphorus fertilizer

Test your soil first so you know where you are starting. Color changes take time: start amending in fall or early spring, and expect a gradual shift over one or two seasons rather than overnight. Overdoing aluminum sulfate can burn roots, so follow label rates and water it in well. Plants in containers are much easier to color-shift because you control the potting mix.

Pruning Bigleaf Hydrangeas

This is where most bloom failures start. Traditional mophead, lacecap and Nikko Blue hydrangeas bloom on old wood: the flower buds for next year form at the tips of this year’s stems in late summer and fall.

• When: prune only right after the plant finishes flowering in summer, and finish by early August in most regions. After that, you are cutting off next year’s buds.
• Deadheading: snip spent flowers back to the first set of large, healthy leaves below the bloom. Many gardeners leave the last flowers on through winter for interest and some bud protection, then remove them in spring.
• Spring cleanup: wait until buds swell and leaves start to open, then cut out only dead stem tips above the highest live buds, and remove any fully dead stems at the base.
• Renewal: on older, crowded plants, cut one or two of the oldest stems to the ground each summer after bloom to keep the shrub vigorous.
• Never: shear the whole plant in fall or early spring.

Reblooming varieties are more forgiving because they also flower on new growth, but you still get the most flowers by pruning lightly. See our step-by-step guide to pruning hydrangeas for photos of where to cut.

Winter Protection

Bigleaf hydrangea roots are hardy in zone 5, but the stems and the buds on them often die back in zone 5 and in hard zone 6 winters. Dead stems mean no flowers on old-wood types. Protection helps:

• After a few hard frosts, mound 6 to 12 inches of shredded leaves or mulch around the base.
• In zone 5 and exposed zone 6 sites, surround the plant with a cage of chicken wire or burlap and fill it loosely with dry leaves. Remove it in spring once hard freezes are over.
• Keep watering in fall until the ground freezes; dry plants suffer more winter damage.
• Watch spring forecasts. When a frost is predicted after new leaves emerge, cover the plant overnight with frost cloth or an old sheet, not plastic.

Common Problems

• No flowers: usually pruning at the wrong time, winter bud kill, late frost, too much shade or too much nitrogen. Our guide on why hydrangeas do not bloom walks through each cause.
• Brown, crispy leaf edges: drought or too much afternoon sun.
• Leaf spots: fungal leaf spots are common in wet summers and mostly cosmetic. Water at the base and remove badly spotted leaves.
• Powdery mildew: white coating on leaves in humid weather with poor airflow; thin crowded stems and improve spacing.
• Aphids and spider mites: hose off aphids; mites show up as stippled leaves in hot, dry weather and respond to regular watering and a spray of water under the leaves.
• Flowers turning brown early: heat, drought or hot sun on the flower heads; more afternoon shade and consistent watering help.

Bigleaf Hydrangea Care Calendar

• Early spring: remove winter cages once hard freezes pass; wait for buds to swell before trimming dead tips; apply color amendments if needed.
• Spring: feed lightly as leaves emerge; refresh mulch; cover new growth if late frost threatens.
• Early to midsummer: water deeply through heat; enjoy the main bloom.
• Right after flowering: deadhead and do any shaping or renewal pruning, finishing by early August.
• Fall: keep watering until the ground freezes; do not prune; mound mulch and set up winter protection in zone 5 and 6.

Bigleaf Hydrangeas in Containers

Compact bigleaf varieties grow well in large containers, at least 18 to 24 inches wide, with drainage holes and a quality potting mix. Container plants dry out fast, often needing water daily in summer. In zone 7 and colder, move pots into an unheated garage or shed for winter so roots and stems do not freeze solid, and water lightly once a month. For more perennials and shrubs that pair well with hydrangeas, explore our flowers and perennials hub.