Georgia Gardener Newsletter

Georgia Gardener Newsletter Cool Plant: July 12, 2007

Summersweet

Clethra alnifolia

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Species Native Range: Eastern U.S.
Hardiness: USDA Zones 4-9
Mature Size: 3-8 feet tall, suckering
Exposure: Full sun to partial shade
Soil: Rich soil that is average to wet
Ease of Culture: Easy

Clethra is one of the most versatile shrubs (native or not) that you will find in the nursery. It's natural environment is in damp/wet to periodically flooding soils at the edges of swamps and rivers where it receives full sun to partial shade. However, once established it's very drought tolerant and does well in average to dry soil. Flowering occurs in mid to late summer and is best in sun.

There are several cultivars of this plant available which range in size and flower color:

Hummingbird: 3-4 feet tall, white flowers (pictured above)
Ruby Spice: 6-8 feet tall, red-pink flowers
Pink Spires: 6-8 feet tall, pink flowers that fade to white
September Beauty: 5-6 feet tall, white flowers
Sixteen Candles: 2-3 feet tall, white flowers
Rosea: 6-8 feet tall, pink flowers that fade to white

All varieties of this plant will sucker which in the right environment can be useful. Because of this, Summersweet makes a good choice for controlling mild to moderate erosion on banks.

Grow Summersweet in a shrub border, at the edge of a woodland garden or along ponds and streams. It attracts both hummingbirds and butterflies with its fragrant flowers.

Summersweet mixes well with other sun-loving, wet soil plants such as Little Henry Itea, Fothergilla, Swamp Hibiscus, Swamp Sunflower, Joe-pye Weed, Winterberry and Buttonbush. In average garden soil, it looks great with Loropetalum, Knockout Rose, Black-eyed Susan, Purple Coneflower and Purple Muhly Grass.

Sources:

Summersweet and its cultivars are widely available at retail nurseries.