Berries for Birds.
We’re well into fall, so it’s a great time to think about how you can help our migrants and over-wintering birds with your planting choices as they face the challenge of migration or cold weather. Viburnums are an excellent choice for both purposes.
Viburnum triloba
What are Viburnums?
Viburnum is a genus of fruit-bearing shrubs, with a few that can even grow to the height of a small tree. There are non-native Viburnums, some of which are commonly sold in nurseries and big box stores, but they don’t have the wildlife value of our native viburnums. We’re talking about the native ones here.
Most of our native viburnums feature flat-topped white flower clusters in spring, attractive green foliage in summer, and a splash of fall color with leaves that turn yellow or red, depending on species. They serve as host plant for a number of butterflies and moths, including the tiny blue spring azure butterfly and the amazing hummingbird clearwing moth. Most importantly, they produce berries that ripen in late summer or fall that are very attractive to birds. More on that below!
The two species that I have at my house are V. nudum, known as smooth witherod or possumhaw (don’t ask me to explain those common names), and V. trilobum (also known as V. opulus var. Americanum), common name American cranberrybush or cranberrybush viburnum. As you might guess, the latter has shiny red berries that somewhat resemble cranberries. The former has clusters of deep blue berries, like most of the native viburnums.
Viburnum nudum 'Winterthur'
A Winner for Migrating Thrushes
Migration is an energy-intensive activity. Songbirds travel at altitudes as high as 500 to 2,000 feet and can cover several hundred miles in a night. Along the way, they face many hazards such as stormy weather. They need to fatten up to power their journey before migrating, and they feed during stopovers along the way, too. Many songbirds that eat protein-rich insects during the summer switch to eating more berries in the fall for their fat. Berries with a high fat content are especially valuable, and viburnums fit the bill. With fat content of 40% or more, viburnums far outdo some of the non-native invasives such as multiflora rose and Japanese honeysuckle, which have numbers under 1% according to one source. You’ll see birds feeding on the abundant berries of these non-natives, but it’s like eating junk food—the birds will not get the nutrition they need to have a good body condition for migration.
Hermit Thrushes are birds that breed in the northern U.S. and Canada and move to the southern U.S. for the winter. They nest in forests and are unlikely to be in your backyard during the summer unless you’re in or near a good-sized woodlot. But they really love viburnum berries, and that can be a great way to see one in your own backyard. I have several large Viburnum nudum bushes that put out big clusters of berries, and most Octobers I get a Hermit Thrush dropping in to eat them. Usually they hang around for several days at a time. One year, a Hermit Thrush even stuck around until early January. (A few typically do linger in our region through the winter and are recorded on the Christmas Bird Count, so this behavior is not super unusual—but they’re usually found in the woods, not in a backyard in Allentown!)
If you live in a less urban area, you may find other fall migrants making use of your viburnums, too. If berries linger into spring, returning migrants such as catbirds, phoebes, and grosbeaks may take advantage.
Popular with Winter Birds, Too
Of course, birds that stay with us through the winter need plenty of energy to survive the cold. Some of our year-round residents that eat insects in warm weather turn to berries to make it through the winter. When my viburnum berries are ripe, a Northern Mockingbird usually shows up and hangs around for a week or two. Cardinals and Robins also love the berries. Although I haven’t seen them eating these berries in my yard, Northern Flickers, Cedar Waxwings and Eastern Bluebirds are also wintering birds that are listed as attracted to viburnum berries.
Viburnum nudum 'Winterthur'
A Viburnum for Everyone
Chances are good that you can find a Viburnum to fit your needs! Besides the species I’ve already mentioned, other commonly used native viburnums include arrowwood viburnum (V. dentatum), nannyberry (V. lentago), and blackhaw (V. prunifolium). Like the other two, these are versatile and can take a variety of conditions. They vary in height and width, though, and some are more tolerant of dryness while others will be more tolerant of wet soil. Be sure to read plant tags and talk to nursery personnel before picking out the viburnum that is best for your space.
Note: There are some native cultivars that may be smaller and more compact or have other attractive properties for your needs. These sometimes require a second plant nearby for fertilization, so be sure to ask if you’re buying one of those. Certain cultivars need a different variety nearby for successful cross-pollination, so again, check when you buy.
Fall is for Planting
We tend to think most about adding to our gardens as the earth starts to come alive after winter. Somehow, the smell of spring in the air makes us want to start digging and adding to the emerging life. And there’s nothing wrong with planting then. But as people in the nursery business like to say, “Fall is for Planting.” Fall is actually a great time to put plants in the ground. With cooler temperatures, new plantings suffer less heat stress, and it’s easier to keep them moist. Plus, their roots have time to settle in and take hold before the spring growth spurt. So don’t pass by the chance to add something for the birds this fall! You can plant any time until the soil freezes.
Barbara Malt, Vice President of the Lehigh Valley Audubon Society, author and all photo credit