The Butterfly Garden Habitat at the Smithsonian’s National Museum of Natural History is full of colorful landscape during the winter months. James Gagliardi, Smithsonian Gardens horticulturist, shares eight ways to brighten your winter garden. Here are some of the tips he uses in the Smithsonian gardens.
The Brassica family (Brassicaceae) provides many great plants to add color to the winter garden. In the Butterfly Habitat Garden there are a variety of these family members, including kale, cabbage, mustard, broccoli, Brussels sprouts and kohlrabi. Not only do they add visual interest, they are a great ingredient to many recipes! Some of the standouts for visitors this season have been the “Dinosaur” and “Red Bor” kale as well as “Early Purple Vienna” kohlrabi.
River birch (Betula nigra “Cully” Heritage) becomes the center of attention after the leaves fall. This tree features exquisite exfoliating bark that peels from the trunks in papery strips of salmon, orange and tan tones to reveal the young ivory bark beneath. The pealing bark provides a place for butterflies to hibernate and hide from predators.
Common witch hazel (Hamamelis virginiana) blooms with a unique fragrant yellow flower with four wavy strap-like petals as early as October and as late as December. The flowers are a nectar source for migrating insects in the later part of the year. The resulting seed pods from this pollination take a full year to mature. Mature seed capsules explode open, launching seeds as far as 30 feet where a new plant may grow if not found first by a foraging bird.
Switch grass (Panicum virgatum “Cloud Nine”) is especially stunning when highlighted by the sun to form a cloud of bright gold in the winter landscape. The plant adds great structure and serves as a larval host to the Delaware Skipper butterfly. Plus, like many grasses, the seeds feed song and game birds, and in spring it becomes popular nesting material.
Winterberry (Ilex “Sparkleberry”) is an absolute standout in any winter garden. A hybrid selection made by the National Arboretum, this deciduous holly is covered in brilliant red berries throughout the winter. For a heavy production of berries, which attract songbirds, a male pollinator will be needed because Sparkleberry is female.
The Tatarian dogwood (Cornus alba “Bud’s Yellow”) marvels visitors with its bright yellow twigs. One of the few non-native plants in our landscape, it shows a stronger resistance to canker, or plant diseases, which can devastate our native Yellow Twig dogwood (C. sericea “Flaviramea”). A true multiseason plant, the shrub features showy flat arrangements of white flowers in late spring that will later yield a cluster of white berries—a tasty snack for birds.
Wild senna (Cassia marilandica) has attractive seed pods that add interest and whimsy to the garden. The dried black pea-like capsules stay closed late into the winter when the seeds drop to feed foraging game birds like wild turkey and quail. This native plant is the host plant of various sulfur butterfly species.
This list would not be complete without mentioning pansies and violas, which have become a late season staple in the garden. This year more than 1,200 “Sorbet Lemon Blueberry Swirl” horned violets were planted around the National Museum of Natural History. Apart from their cheery name, these violets have a great ability to overwinter. At the north entrance of the museum the violets are mixed into a border of “Red Bor” kale and “Toffee Twist Sedge” to add color, texture and interest.