It’s late winter! And that means we should be talking about summer – Summersweet that is.
Coastal Sweet Pepperbush (Clethra alnifolia), also known as Summersweet, may not be what you think about in March but it is an important year-round habitat shrub for vertebrates and invertebrates alike. And now is the time for planning spring plantings.
Sweet pepperbush is naturally found in Maryland on the coastal plain and piedmont, Carroll County, and all points east and south. Its full range extends from Nova Scotia to Florida and west to Texas. It’s a medium shrub, growing up to 10 feet tall, and it likes wet feet. You’ll find it in acidic swamps, moist woods, and at the edges of wetlands and streams, as it is very tolerant of clay and moist soils. It loves full shade but is tolerant of partial shade and even full sun. Despite its love of moist soils, it is surprisingly drought tolerant once it is established. It can spread by rhizomes (a sort of underground stem), making it an easy plant to use as a grouping or hedge. But it is not particularly fast growing, so you don’t have to worry about it taking
over the yard.
The foliage is a medium to dark green, and it is late to leaf out in the spring. The leaf margins are serrated toward the tip but smooth near the petiole. They are ovate to oblong, alternately arranged, 2-3 inches long. The leaves turn brilliant gold in the autumn. The style of leaf is what gives this plant its scientific name. Someone - we’re looking at you, Linneaus - thought it looked like an alder. “Clethra” comes from the Greek for alder, while alnifolia means “alder- leafed.” Ironically, this plant is not in the alder family, Betulaceae, but in its own family, Clethraceae.
Its value as wildlife support is manifold. In mid-summer, its sweetly fragrant white flowers arranged on a raceme, or spike, are a huge draw for bees, both native and honeybees, for nectar and pollen. Butterflies and hummingbirds are also drawn in by the nectar bounty of this mid- to late summer flowering shrub. Once the flowers are done, the seed capsules persist on the stems, providing a valuable seed source for migrating and overwintering birds from late fall into winter. This is also where it gets the name pepperbush. The seed capsules look a little like peppercorns, but they offer no culinary or medicinal properties.
It is not a preferred plant of
deer or other browsers, so it can make an excellent anchor plant in native landscaping. Use a full species, not a cultivar. Research suggests full species provide more nectar than cultivars. Then set up a lawn chair and watch the summer
pollinator jamboree!
If you’re in the region west of Carroll County, consider planting ninebark (Physocarpus opulifolius). It has similar wildlife value, similar planting needs (although it prefers a little more sun), flowers May through July, and very interesting shreddy bark. Again, stick with the
native species and avoid the cultivars if peak wildlife value is your goal.
Additional Resources:
https://vnps.org/wildlfower-of-the-year-2015-clethra-alnifolia-sweet-pepperbush/
https://www.fws.gov/media/native-plants-wildlife-habitat-and-conservation-landscaping-chesapeake-bay-watershed
https://pollinatorgardens.org/2013/02/08/my-research/
https://piedmontmastergardeners.org/article/native-species-or-cultivars-of-native-plants-does-it-matter/
