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Shrubs

Clethra alnifolia

summer sweet

An erect, bushy, suckering shrub not usually exceeding 2m. The fresh green leaves are simple, obovate, neatly serrrate, sometimes turning yellow in autumn. Near-white scented flowers are abundantly produced, in erect terminal racemes, in summer. Pink selections are available

Other common names

bush pepper
common white alder
see morenana
pink spire
sweet pepper bush

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Ultimate height

1.5–2.5 metres

Time to ultimate height

5–10 years

Ultimate spread

1.5–2.5 metres

Clay

Loam

Sand

Moisture

Moist but well–drained

pH

Acid

	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Full shade
Partial shade

Aspect

South–facing or North–facing or West–facing or East–facing

Exposure

Sheltered

Hardiness
Hardiness ratings
All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets
H1a: under glass all year (>15C)
H1b: can be grown outside in the summer (10 - 15)
H1c: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20)

Botanical details

Family: Clethraceae
Native to GB / Ireland: No
Foliage: Deciduous
Habit: Bushy
Genus: Clethra can be deciduous or evergreen trees or shrubs, sometimes with attractive bark, with simple leaves and small, fragrant, usually white, bell-shaped flowers in racemes or panicles
Name status: Correct
Plant range: E N America

How to grow

Cultivation

Grow in fertile humus-rich moist but well-drained acid soil, best in part or dappled shade

Propagation

Propagate by seed in spring or autumn; propagate by softwood cuttings in early summer

Suggested planting locations and garden types

Cottage and informal garden
Low Maintenance

Pruning

Pruning group 1; remove some of the old wood from the base in winter, leaving the strongest suckers as replacement growth

Pests

Generally pest-free

Diseases

Generally disease-free

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