Clethra alnifolia, commonly referred to as summersweet and sweet pepperbush, might be a treasure for wildlife within its perennial range, U.S. Department of Agriculture plant hardiness zones 3 through 9. Its aromatic blooms and peppercornlike seeds beckon winged wildlife, attracting those guests into the yard.
Summersweet supplies two food sources for birds: nectar and seeds. In midsummer, the plant creates flower panicles, which start flowering in the bottom upward until they resemble bottle brushes. Hummingbirds appear to discover the sweet nectar from the spicy-fragranced blossoms irresistible. Following a flowering period which generally starts in July and lasts six weeks, the flowers fade and give way to brown seed capsules. The seed capsules offer food for other birds well into autumn. It’s the appearance of the peppercornlike seeds which gives summersweet its other common name — sweet pepperbush.
Summersweet’s aromatic flowers also attract pollinators like butterflies, bees and wasps. Should you grow summersweet as a butterfly-garden plant, its natural pest- and also disease-resistance means you do not need to use chemical pesticides, that may kill butterflies. Bees are also vulnerable to toxic substances. Some cultivars of summersweet are bred for different flower colors and shapes, but the common selection of the species might often produce more nectar than the cultivars for butterflies.
Offering the environment that summersweet prefers may keep it in optimum health so that it continues to produce nectar, seeds and pollen for the wildlife it attracts. In summersweet’s hardiness range, the plant tolerates varied light and soil conditions. It thrives in full sun but also prospers in complete colour, flowering in both extremes. It responds to well-draining soil, but it also grows in wet locations, which makes it a acceptable plant for rain gardens. Another one of summersweet’s forgiving traits — salt-tolerance — makes it a candidate for planting in coastal locations.
Based on the size of your wildlife garden, a summersweet cultivar likely is available to match the space. The cultivar “Hummingbird” (Clethra alnifolia “Hummingbird”) is a botanical Sliding magnet that is hardy in USDA zones 3 through 9. Bearing white blooms, it has a height of just 2 to 4 feet and a spread up to 5 feet, making “Hummingbird” acceptable for a little wildlife garden. If you want a flowering tree to fill a narrower vertical space, then consider “Ruby Spice” (Clethra alnifolia “Ruby Spice”), that grows up to 6 feet in height with a spread of 3 to 5 feet. It includes rose-pink flowers and is hardy in USDA zones 4 through 8. In case you’ve got a larger space to fill in your wildlife garden, subsequently “Pink Spire” (Clethra alnifolia “Pink Spire”), one of the largest summersweet cultivars, is an option. This tree may reach 8 feet tall with a 6-foot spread, plus it creates light-pink flowers. “Pink Spire” is hardy in USDA zones 4 through 8.