This is the third column in a series on native shrubs that function in garden ecosystems by providing food, cover, and/or nesting sites for garden wildlife. The first two essays in this series can be found at http://gardeningintunewithnature.bangordailynews.com/author/rmanley/.
The three native shrubs presented below are multi-season plants in Marjorie’s Garden. They provide ornamental interest with their spring flowers, colorful fruits, and beautiful autumn foliage while providing food for garden birds, insects, and other wildlife.
Mapleleaf Viburnum (Viburnum acerifolium)
Native range: Eastern half of the U.S. to the Mississippi River; also Louisiana, Missouri, and Texas.
There was a time when the arrowwood viburnum (V. dentatum) would have topped anyone’s list of native shrubs for the bird garden, but the viburnum leaf beetle’s preference for this species has removed it from many gardens in New England. There are, however, native viburnums that are less susceptible to the beetle and, based on a decade of experience growing mapleleaf viburnum in Marjorie’s Garden, I am recommending it for use throughout its native range. A forest understory shrub in the wild, this shade-tolerant viburnum has a robust suckering habit that will create a dense stand of six-foot-tall stems in open areas of the garden.
Mapleleaf viburnum is an excellent fruiting plant for birds, including ruffed grouse, brown thrashers, cedar waxwings, and sparrows, although there have been years when some of the purple-black fruits remained on the shrubs in our garden until April before they were finally taken. This may be due to their relatively low fat content. Chipmunks and red squirrels will also eat the berries, but in some years the viburnum berries in our garden seem to be the exclusive property of white-throated sparrows. It appears odd to see these ground-scratching little birds hopping from branch to branch, stretching their necks to reach berries hanging just out of reach. A flock of ten or so sparrows arrives on an appointed day known only to them and a few days later the viburnum branches are bare. We count it as a good trade, berries for their sweet whistle, Old-Sam-Peabody-Peabody, heard even in winter.
In autumn, mapleleaf viburnum’s leaves are painted with the colors of an October sunrise, French rose pink with purple blotches between the veins, leaf colors not found in any other plant. At the same time, the slightly flattened oblong berries mature to a glossy blue-black. For a short time in early October, before the fruits are taken by the birds, this combination of colors is one of the highlights of our autumn garden.
Winterberry Holly (Ilex verticillata)
Native range: Eastern half of the U.S. to Mississippi River; also MN, IA, MO, AR, LA, and TX.
Found growing in the wet soils of red maple swamps and on the bare shoulders of granitic outcrops, winterberry holly is at home in most gardens. As with all hollies, male and female flowers are borne on separate plants, so in order to have bright red holly berries your garden must have a ratio of one male plant for up to nine female plants. And just any male cultivar will not do, as clones selected from different regions of the country have different flowering times. Fortunately, horticulturists have selected cultivar pairs to ensure proper timing of pollination and an informed nurseryman can advise you on the best male partner for you chosen female cultivar.
Winterberry fruits generally start to ripen in autumn as the foliage begins to turn yellow, although in some years the fruits will turn red while the leaves are still green and for a short time the plants resemble evergreen hollies. As winter approaches, the leaves quickly turn brown and drop, leaving behind a feast for birds, including robins, catbirds, mockingbirds, bluebirds, cedar waxwings, woodpeckers, thrashers, thrushes, chickadees, titmice, game birds, and crows. Fortunately for gardeners, birds tend to leave the berries for our visual enjoyment until a midwinter thaw.
Red squirrels, chipmunks, raccoons, and white-footed mice also eat winterberry fruits and seeds, as do the foxes that visit our garden, usually at night. Thoreau observed the mice, writing that they “run up the twigs at night and gather this shining fruit, take out the small seeds, and eat their kernels at the entrance to their burrows.” A few years ago the winterberries in our garden were taken early, before the first hard freeze, a mystery that remains unsolved. Crow, squirrel, chipmunk, fox, who knows? I like to believe white-footed mice took them for their seeds, scampering up the branches at night to gather the fruits, storing them near near their burrows, perhaps under old tree stumps, for when the snow lies deep over the garden.
Growing native shrubs such as winterberry holly is a decision to be intimately involved with the garden, for much of their beauty is subtle. They are endowed with elusive qualities that we miss unless we look closely, stick our noses or focus our eyes in the right place, in the right season. You must look closely to appreciate the tiny flowers of winterberry in spring, watch attentively as small native bees and flies forage for a nectar shared with migrating butterflies, including the Painted Lady, the Red Admiral, and the Question Mark. Winterberry holly also serves as a larval host for the Henry’s Elfin butterfly.
Highbush Blueberry (Vaccinium corymbosum)
Native range: Eastern half of the U.S. to Mississippi River; also LA, AR, OK, TX, WA
In June and July, Marjorie and I go to the garden to watch native bumblebees pollinate highbush blueberry blossoms as they forage for nectar. They are a joy to watch as they forage from first light to last, stopping to rest only in a cold rain when they seek refuge under a leaf or flower cluster.
On dewy mornings in August, when the branches of the shrubs are bending under the weight of ripe fruit, we will walk through wet grass to the garden, each grasping a mug of steaming coffee in one hand, a bowl for berries in the other. Holding a cupped hand beneath a cluster of berries –
some further along toward full ripeness than others – and moving my fingers over the berries as if tickling the bottom of a child’s foot, the ripest berries will break the fragile connection with their slender stalks and fall into my hand, dark purple-black fruits bursting with sweetness.
As if the spring flowers and summer fruits were not enough, highbush blueberry shrubs delight us again in October with their scarlet red and golden yellow leaves. On close inspection, not every leaf is the same shade of red and some are barely red at all. Some of the blueberry leaves hang
on long enough to be kissed by a late October freeze, their leaves covered with needles of ice.
In addition to enriching our lives, both nutritionally and aesthetically, and the lives of native bumble bees, highbush blueberries are connected to many other creatures in the garden food web. Songbirds that eat the berries include tufted titmice, red-eyed vireos, robins, bluebirds, scarlet tanagers, towhees, catbirds, mockingbirds, brown thrashers, cardinals, and orioles. Grouse, both ruffed and spruce, also enjoy the fruits, as do small mammals, including white-footed
mice, chipmunks, and striped skunks. V. corymbosum is also a larval host plant for several lepidopteran species, including the brown elfin, striped hairstreak, spring azure, and hummingbird clearwing butterflies and the major datana and saddleback moths.
In spite of the popularity of highbush blueberries among the garden’s other creatures, Marjorie and I manage to harvest enough ripe berries to satisfy our cravings for fresh summer berries while putting up jars of dehydrated berries for winter. We’ve learned to pick them just as they fully ripen. Leave them longer and they belong
to the garden’s wildlife.