Wildlife in the Winter Garden

American holly (Ilex opaca).

Did you know Smithsonian Gardens joined Audubon International’s Cooperative Sanctuary Program? The goal is for the gardens and greenhouses at the Smithsonian to be designated as a Certified Audubon Cooperative Sanctuary. To become certified, Smithsonian Gardens has developed, implemented, and documented the results of an environment management plan in five key areas: site assessment and environmental planning, wildlife and habitat management, water, resource management, and outreach and education. We believe that Smithsonian Gardens has met (or in some cases exceeded) Audubon International’s environmental management standards in all five areas. We are looking forward to a site visit from an Audubon International staff member to verify Smithsonian Gardens submission.

Below is a list of plants that you can find in the Smithsonian Gardens that are native to the mid-Atlantic region and provide food and shelter to wildlife during the winter months.

• Ilex glabra, also called inkberry, is an evergreen shrub with black fruit called drupes. The fruit, attractive to birds, appears September through March. You can find this shrub in the Urban Bird Habitat Garden at the National Museum of Natural History.
• Ilex opaca, known as American holly, can be found on the south side of the Smithsonian Castle in the Enid A. Haupt Garden. This large evergreen tree provides nesting opportunities for birds and small mammals as well as bright red berries to sustain our feathered friends during the cold winter months.
• Ilex verticillata is a deciduous holly often called winterberry. Birds really seem to enjoy these beautiful berries so don’t forget that winterberries are dioecious, meaning that the berry-producing female plants need a male winterberry nearby to produce fruit. Look for Ilex verticillata on the north side of the National Air and Space Museum due east of the entrance.
• Lindera benzoin is called spicebush because of the spicy smell of the leaves when crushed.  We grow this tree for its year-round wildlife value. This tree is a host plant for the Spicebush Swallowtail butterfly and the fruit is eaten by songbirds. You can find this understory shrub in the landscape of the National Museum of the American Indian as well as in the Butterfly Habitat Garden at the Natural History Museum.
• Rhus typhina ‘Dissecta’ or staghorn sumac as it is commonly called is not only a picturesque plant but a source of reddish brown seeds that are consumed by many birds and small mammals throughout the winter months. The staghorn sumac is also a host and nectar plant for both moths and butterflies which is why you can find it in our Butterfly Habitat Garden.

Staghorn sumac (Rhus typhina ‘Dissecta’)

For more information on native plants for wildlife habitat: http://www.nps.gov/plants/pubs/chesapeake/pdf/chesapeakenatives.pdf

For more information about the Audubon International’s Cooperative Sanctuary Program:
https://www.auduboninternational.org/acsp 

–Shelley Gaskins, Smithsonian Gardens Horticulturist, Green Team Member 

Janet and the Beanstalk

Some things start innocent enough—and that is how this story begins.

Last year, the horticultural staff from Monticello came up from Virginia for a tour of the Smithsonian Gardens and brought me a goody bag of seeds they thought I might find interesting.  Somehow they knew I have “a thing” for plant oddities. The goodies included things like Medicago or ‘Snail Clover,’ which has these BEAUTIFUL spiral seeds which look like beads, and Mimosa pudica – a sensitive plant that folds up when you touch it, and something mysterious called ‘Guinea Bean’ or ‘Snake Gourd’.

I had never heard of Guinea Bean so I looked it up and learned that it is actually a gourd, native to Mediterranean areas.  In Italy it is known as “Cucuzza” which translates to something like ‘super long squash’. The descriptions all say it is edible and looks like a zucchini, gets 15” to 3’ long and is treated much like a zucchini.  Harvest it small and it tastes like green beans, harvest it later and has more solid flesh. Unlike a zucchini, it does form a hard outer shell when left on its own.

Armed with that information, I was willing to try it, especially because part of the Mary Livingston Ripley garden is behind the construction fencing for the Arts and Industries Building restoration project so I could grow it on the fence, out of public view.

I really did not think much of these little squash-like plants when I put them out in early spring. I honestly forgot about them until the weather got warmer and the plants started putting on growth, which required me tying them to the lattice fencing. I thought they would get to the top of the 6’ fence and stop there. Boy, was I ever wrong!

I first noticed sometime in July that a couple of the plants had reached out and grabbed onto the protective netting beyond the fence that was surrounding the scaffolding on Arts and Industries Building. I thought it was cute, and would add ammunition to my perpetual prank battle with the construction crews. It took just a few days until I started getting  ’threats‘ of a bill coming from the scaffolding company for use of “their” trellis.  And the plant kept growing. Soon I started getting all kinds of inquiries from the construction guys asking what it was. They could actually measure the growth of the vine from morning until the end of their shift! It was literally growing 1-3 feet a DAY! Everyone wanted to know what it was and how big it would get. I relayed what I had gleaned from my quick search, but noticed that no one was saying how big the plants grew . . . hmm . . . wonder why?

The Guinea Bean plant shot straight up the side of the Arts & Industries building scaffolding.

As the summer progressed the guys continued to report in their findings, including a baseball bat-sized gourd hidden on their side of the fence. Wow – it was a honker – much larger than the 3’ maximum . . . how much bigger could it get?  So of course, we left it to grow.

By August the plants had almost reached 30 feet tall, and I saw that the scaffolding crews were removing the netting from the scaffolding.  Bummer!  The plant would not have the chance to make it to the top of the building.  But I was delighted that, without even consulting me, they removed all the netting except the one with the gourds! They wanted the plants to make it to the top also!

So . . . did the ‘Snake Gourd’ make it? Yes! Our Jack-and-the-beanstalk plant climbed to 50 feet to reach the top of the scaffolding.

Janet poses with three of her very long Guinea Bean gourds grown in the Ripley Garden.

Only three gourds actually made it—the big honker we found early in the season matured to a little over 5 feet long, with a solid outer shell, plus a skinny wobbly 5’ long one plus a soft tender 3’ gourd.  All of which I dragged home on the Metro which caused much bewilderment to all who saw me and information and education for those who were curious enough to inquire.

And this all started with the sharing of some innocent looking seeds. Thanks for the adventure to my friends at Monticello! Remember, January is National Mail Order Gardening Month. What are you ordering to plant in your garden?

-Janet Draper, Smithsonian Gardens Horticulturist 

Winter Interest in the Garden

Just because it is winter does not mean that our gardeners or gardens get a rest.  Smithsonian Gardens welcomes visitors year-round.  These visitors include many tourists but also wildlife, as our gardens serve as an important urban habitat for birds, insects, and mammals.

Within our gardens you will find many plants that add winter interest beyond our impressive annual displays of pansies, violas, and kale.  Important garden features in this bleaker season include berries, grasses, seedheads, stems, bark, evergreens, and even some flowers.

Fruit and berries are a great way to brighten up a winter landscape and many serve as an important food source for birds.

Berries you will find in our gardens include (clockwise from upper left) Red Chokeberry (Aronia arbutifolia); American Holly (Ilex opaca); Firethorn (Pyracantha ‘Mohave’); Southern Bayberry (Morella cerifera); Beautyberry (Callicarpa dichotoma); Carmine Crabapple (Malus x atrosanguinea); and Winterberry (Ilex verticillata)

When selecting plants for winter berries note whether they are deciduous or evergreen.  The pointed rich green leaves of the American Holly above create a great contrast to the bright red berries while the Winterberry (Ilex ‘Sparkleberry’) below looks better with a solid backdrop like an evergreen to best stand out.

Winterberry (Ilex ‘Sparkleberry’)

Grasses and sedges add texture to our gardens in winter and some add great color as well.  Many of the grasses also provide seeds for birds in winter and nesting materials come spring.

Some of the grasses and sedges you will find on our gardens include (clockwise from upper left) Leather leaf sedge (Carex buchananii ‘Red Rooster’); Switch Grass (Panicum virgatum ‘Cloud Nine’) [close-up and full plant]; Orange New Zealand Sedge (Carex testacea); and Pink Muhlygrass (Muhlenbergia capillaris) [pictured in November and January]

Seedheads create interest with varying shapes and textures and make a dynamic feature in winter as they mature and disperse.

Seedheads and pods that draw attention in our gardens include (clockwise from upper left) False Indigo (Baptisia australis); Purple Coneflower (Echinacea purpurea); Okra (Abelmoschus esculentus); Common Milkweed (Asclepias syriaca); Goldenrod (Solidago spp.); Whitehair Leather Flower (Clematis albicoma); and Upland Ironweed (Vernonia glauca)

Remember these seedheads are the result of earlier flowers from plants that have multiple seasons of interest.  Some of these seeds are now food sources for birds,  but their flowers were nectar sources, or some had foliage that fed caterpillars, in earlier seasons.  Take the Wild Senna (Senna marilandica) below, for example. It is a wonder native plant with nectar-providing pea-like flowers and is a host plant for sulfur butterflies in the summer.

Wild Senna (Senna marilandica)

Differing barks and branches also play a significant role in enhancing our gardens in winter.  Peeling barks of birches, brightly-stemmed twig dogwoods, and the towering dry stems of perennials can all become dominant features in the winter.

Some of our most striking stems in the gardens are seen with (clockwise from upper left) Paper Birch (Betula papyrifera ‘Renci’); River Birch (Betula nigra ‘Heritage’); Hollow Joe Pye Weed (Eutrochium fistulosum); Tatarian Dogwood (Cornus alba ‘Bud’s Yellow’); Coral Bark Japanese Maple (Acer palmatum ‘Sangokaku’); Crape Myrtle (Lagerstroemia ssp.); Red Twig Dogwood (Cornus sericea ‘Baileyi’); and Paperbark Maple (Acer griseum)

Evergreens are a key element to add structure in gardens during the winter.  There are a variety of evergreens available with a myriad of shapes, textures, and even colors.  Evergreens can be needled conifers but also broadleaf trees and shrubs and even some perennials hold their foliage in the winter months.  They also provide important cover and shelter for many species in winter.

A small sampling of our many needled evergreens include (clockwise from upper left) Eastern Redcedar (Juniperus virginiana ‘Burkii’); Umbrella Pine (Sciadopitys verticillata); Irish Yew (Taxus baccata ‘Fastigiata’); Japanese Cedar (Cryptomeria japonica); and Scotch Pine (Pinus Sylvestris ‘Burghfield’)

Some of the more dominate broadleaf evergreens in our gardens are (clockwise from upper left) Southern Magnolia (Magnolia grandiflora); Lantanaphyllum Viburnum (Viburnum x rhytidophylloides); Sweetbay magnolia (Magnolia virginiana); English Cherry Laurel (Prunus laurocerasus ‘Otto Luyken’); Common Boxwood (Buxus sempervirens); and Oregon Grape (Berberis aquifolium)

Lastly we can’t forget about winter flowers.  There is not much that blooms at this time but those flowers that do truly give us reason to celebrate.  They are also important nectar source for late and earl- season pollinators.

Blooms you can spot in Smithsonian Gardens in winter are (clockwise from upper left) Lenten Rose (Helleborus x hybridus); Common Witchhazel (Hamamelis virginiana); Sasanqua Camellia (Camellia sasanqua ‘Jean May’); Paperbush (Edgeworthia chrysantha); Stinking Hellebore (Helleborus foetidus); and Beale’s Mahonia (Berberis bealei)

I encourage you to take a walk through our gardens on a nice winter day and see what interesting plants you spot.

-James Gagliardi, Smithsonian Gardens horticulturist