Native Shrubs for Pollinators
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SupportSupport PollinatorsPollinators withwith NativeNative ShrubsShrubs BY JAMES GAGLIARDI AND HOLLY WALKER Provide a pollinator smorgasbord through the seasons with these adaptable, deciduous plants. ollinators are an integral part of our gardens and ecosystems. PHowever, loss of habitat, reduction in the number and quality of food sources, and indiscriminate use of pesticides and herbicides have taken a heavy toll on pol- linator populations everywhere. Gardeners can be part of the solution by creating land- scapes that support pollinators of all kinds. Top: A mix of perennials, shrubs, and trees in the Smithsonian Gardens provides an ideal habitat While pollinator or “butterfly” gardens for a variety of wildlife in the heart of Washington, D.C. Bottom: Thriving in a sloped bed bordering consisting of just annuals and herbaceous a parking lot near the Bird Garden, ‘Henry’s Garnet’ Virginia sweetspire draws butterflies and bees perennials are quite common, the addition with its fragrant spring blooms. Opposite page: The spherical, white blooms of buttonbush grab the of shrubs, trees, and vines greatly enhanc- attention of passersby and pollinators alike. es their habitat value. in the smithsonian Gardens in Washington, D.C., where we From a gardening perspective, not only help us to serve pollinators throughout work, we use all these plant types to draw are these tough shrubs relatively unfussy the seasons, from early in spring when the pollinators year-round. But among the about growing conditions and adaptable first insects emerge from dormancy to fall most versatile workhorses are the decidu- to gardens across most of the country, when they start preparing for winter. ous native shrubs that support a wide range they provide multi-season interest to the of pollinators as well as some very special- landscape in the form of flowers, berries, Spring BloomerS ized ones. bark, and fall color. the following species Virginia sweetspire (Itea virginica, UsDa NSON H O J LIARDI (2). OPPOSITE: BILL G A G AMES J E: COURTESY OF G IS PA H T September / October 2018 17 Red chokeberry features dainty spring blooms (left) that are followed in autumn by small red fruits (above), which become palatable to birds after exposure to low temperatures. We love pairing it with oakleaf hydrangea (Hydrangea quercifolia, Zones 5–9, 9–1), Hardiness Zones 5–9, aHs Heat Zones and black chokeberry (Aronia melanocarpa, another native shrub that thrives in simi- 9–1) is a versatile plant in the smithsonian Zones 3–8, 8–1) are useful for mass plant- lar growing conditions along a woodland Gardens. it is prominently featured in an ings or for mixing into a naturalized pe- edge and also has colorful fall foliage. after understory planting at an entrance and rennial border. fothergilla has completed its blooming, beside a nearby parking lot where it helps Dwarf fothergilla (Fothergilla gardenii, oakleaf hydrangea will continue the show retain a sunny slope. it thrives in both lo- Zones 4–8, 8–1) has showy, scented bot- with large, white, pyramidal panicles of cations, but the blooms are best in full tlebrush inflorescences that emerge from flowers from May to July that will draw sun. its spires of fragrant, white blossoms March to May before its leaves. Bees find in flower flies and wasps along with bees. draw nectar-loving insects like butterflies a sweet nectar reward once they get past running serviceberry (Amelanchier sto- and bees. the plant’s rich red-to-purple the flowers’ dense tangle of anthers. orna- lonifera, Zones 4–8, 8–4) is another plant fall color, especially showy in a mass plant- mentally, fothergilla is a lovely three-sea- that has the benefit of showy white blooms ing, will persist into the winter in southern son plant with foliage that turns brilliant in May for pollinators, edible berries in sum- areas where sweetspire is semi-evergreen. shades of yellow, orange, and red in fall. mer, and striking fall foliage. as its name if you notice some of the foliage looking chewed, it might be caused by caterpil- lars of the american holly azure butterfly (Celastrina idella) for which this plant is a preferred host. red chokeberry (Aronia arbutifolia, Zones 4–9, 9–1) supplies a great deal of value to wildlife in our gardens. From March to May, butterflies and native bees such as mason bees, mining bees, and bumblebees enjoy its clusters of white flowers. the foliage provides a food source to some hairstreak butterflies and sever- ANET DAVIS al moths, and its fall color is stunning. J true to their name, red chokeberry fruits, which are produced in summer, have a LIARDI. BOTTOM: G dry, astringent taste. after exposure to A cold weather, however, the fruits become G AMES more palatable to birds, just when other J food sources for them become scarcer. the fruit’s persistence through late winter also adds some interest to gardens during this less colorful season. Both red chokeberry Dwarf fothergilla produces fragrant, nectar-rich blooms that attract bees in spring. TOP (2): COURTESY OF 18 the American Gardener suggests, running serviceberry is a stolonifer- and abundant fruit will grow to only four unique for a member of the pea family. ous shrub and grows about four or five feet to six feet. individual flowers are composed of a sin- tall and wide. Compared to more common- gle petal wrapped around 10 stamens, and ly used serviceberry species—which often Summer StarS provide nectar to bees, beetles, butterflies, develop as multi-stemmed small trees—the the summer-blooming shrubs in the and ants. it is especially important in prai- size of this species makes it perfect for gar- smithsonian Pollinator Garden keep rie ecosystems where it supports native dens where space is at a premium. the pollinator buffet going through the solitary bees as well as the endangered those on the West Coast all the way hottest months. lead plant (Amorpha Karner blue butterfly (Plebejus melissa up to alaska should consider western or canescens, Zones 2–9, 9–1) mixes nicely samuelis). its cousin, California false indi- saskatoon serviceberry (Amelanchier alni- into perennial borders because of its small go (A. californica), is one of the host plants folia, Zones 4–9, 9–4), which can reach habit. Growing only one to three feet tall, of the California dogface butterfly (Zerene a size of 12 feet or more but the cultivar it features gray foliage and spiked clusters eurydice), the state butterfly of California. ‘regent’ selected for its compact habit of iridescent purple flowers that are quite starting in June, buttonbush (Cephalan- thus occidentalis, Zones 5–9, 9–1) produces captivating, fragrant, spherical flower heads that are a magnet to several species of bees and butterflies. they also grab the attention of passersby, so we have placed this shrub Two summer-blooming pollinator favorites are sun-loving lead plant, left, and bottlebrush buckeye, above, which prefers shade. at the entrance to the Pollinator Garden. round, reddish-brown fruits follow, which can last into winter. this plant gets six to 12 feet tall, and though it is adaptable to most growing conditions, it does best in a damp, ANET DAVIS J partly shady location. another great option for shady, con- AVIS D sistently moist areas is bottlebrush buck- LIARDI. BOTTOM: G ANET J A eye (Aesculus parviflora, Zones 5–8, 8–4), G T: GH which draws in a range of pollinators with AMES J spikes of showy, white flowers that appear in June and July. it typically reaches eight . ONDRA. RI J to 12 feet in height, with a similar spread. one of the most popular shrubs with LEFT: NANCY TOP (2): COURTESY OF pollinators in our garden is a cultivar of September / October 2018 19 Above: A bumblebee searches for nectar on summersweet, which blooms in late summer. Top right: With flowers unfurling as early as H January, ‘Purpurea’ Ozark witch-hazel helps to feed pollinators and add color to the landscape when little else is blooming. Bottom right: Common witch-hazel also produces pollinator-attracting flowers during the colder months, after its foliage turns yellow and drops in fall. T: SUSAN A. ROT Chenault coralberry (Symphoricarpos pink berries follow, often persisting well in- nator Garden. its wands of fragrant, white GH 5chenaultii, Zones 4–7, 7–1) called ‘Han- to winter. Chenault coralberry is a hybrid blooms attract a variety of pollinators—in- cock’. it produces small, pinkish flowers in of two north american native plants: pink cluding butterflies, bees, and humming- June and July that are usually covered with snowberry (Symphoricarpos microphyllus, birds—that have evolved to take advantage ENSLEY. BOTTOM RI insects. We have a large grouping of it at the Zones 8–10, 10–8) and coralberry (S. orbicu- of its narrow, tubular inflorescences. it rang- H RACE national Museum of natural History to latus, Zones 2–7, 7–1). each of these parents es in size from two to eight feet tall. G T: help retain a steep slope. these suckering has plenty of landscape and pollinator value Witch-hazel species bookend the GH shrubs only reach about two feet in height in its own right. pollination season in our gardens. Com- . TOP RI but can spread up to 12 feet, so we often mon witch-hazel (Hamamelis virginiana, GH need to trim them back. However, they con- extending the SeaSonS Zones 3–8, 8–1) is one of the last plants to MCCULLOU stantly attract so many pollinators that our summersweet (Clethra alnifolia, Zones 3–9, bloom each year, between october and H OS gardeners refrain from working with these 9–1) is one of the few blooming shrubs you December.