The Botanical Diary
S
Shrubs

Smooth Hydrangea

Hydrangea arborescens
Also known assmooth hydrangea, wild hydrangea

The cultivar 'Annabelle' produces flower heads up to 30 cm in diameter.

Regions
all regions
Colour
white, cream
Smooth Hydrangea (smooth hydrangea, wild hydrangea)
🌸
Bloom
July–September
☀️
Light
Partial shade / тінь
💧
Watering
High
📏
Height
1–2 m
❄️
Hardiness
Zone 3b

Smooth Hydrangea is one of the most beloved ornamental plants in gardening, native to the eastern part of North America. It is an undemanding plant that has captured the hearts of gardeners worldwide thanks to its reliability and prolonged flowering. Unlike the panicle hydrangea, smooth hydrangea is less demanding in terms of growing conditions and more hardy in cold regions — which is precisely why it is so popular in Ukraine.

The shrub is distinguished by enormous flower clusters that appear in summer and persist until autumn. Freshly opened flowers are milk-white, gradually acquiring creamy and sometimes pink tones — this is a natural aging process of the petals. The cultivar 'Annabelle' is a true star among selected forms, with enormous spherical flower heads that can reach 30 cm in diameter. There are also cultivars with flowers that change colour from white to pink throughout the season, such as 'Incrediball'.

In the garden, smooth hydrangea works wonderfully both in combinations with other plants and as a specimen plant. It looks organic alongside astilbe, hosta, and fern — these compatible companions love the same conditions: partial shade and moisture. You can plant smooth hydrangea in hedgerows, use it to brighten garden corners where sunlight is scarce. It coexists peacefully with conifers and makes garden spaces appear fresher.

If you are seeking a plant that will deliver guaranteed results even without experience, smooth hydrangea is just the thing. It is reliable, beautiful, and generous with its blooms. Each summer it gives you luxuriant flowering that lasts until the first frosts, transforming even a modest garden into a true floral paradise.

Location & soil

Smooth Hydrangea — planting & location

LightPartial shade / тінь
Soil typemoist, рН 5–6,5
Planting timeApril або October
Plant spacing1,2–1,8 m
Planting depthAt root collar level

More cold-hardy than Panicle Hydrangea.

Water needs

How to water Smooth Hydrangea

IntensityHigh
FrequencyEvery 7 days (в)
Volume15–20
MethodAt the base

Do not allow the soil to dry out.

Annual care

Fertilizing and pruning: Smooth Hydrangea

Spring fertilizingNitrogen (April–May)
Summer fertilizingNo feeding required
Autumn fertilizingSuperphosphate (August)
Pruning timeApril (до набухання бруньок)
Pruning typeРадикальна

Cut back to 20–25 cm from ground level.

Cold hardiness

Smooth Hydrangea — winter hardiness & care

Hardiness zoneZone 3b
Winter coverNot required (Zones 3–4)
Cover timing
Plant protection

Diseases and pests of Smooth Hydrangea

Diseases
Powdery mildew
Pests
Spider miteAphid
Garden design

What grows well with Smooth Hydrangea?

Гортензія волотиста, астільба, хоста