I Yam Not a Tortoise but a Plant
The caudex of the Dioscorea mexicana.
Dioscorea mexicana, commonly called Mexican Yam or Tortoise Plant, is native to Mexico, El Salvador, and Panama. Dioscorea is made up of around 600 species in the Dioscoreaceae family and has a world-wide distribution range. Originally in the Testudinaria genus and named after ‘Testudo,’ a genus of tortoise, it was later grouped into the genus Dioscorea.
The plant’s caudex (or modified stem) resembles the shell of a tortoise. The caudex itself is a partially exposed tuber that is covered in grayish-brown scales. It is divided into polygonal plates that are scored by deep furrows. This species typically goes dormant during the winter, though this year even without water for nearly four months the stem didn’t die back and still looks great, so we shall see what the future holds. From what I have experienced, heard from other growers, and also read, this plant sometimes either doesn’t die back during the winter or sends out a new stem earlier or later than expected, so watch the plant and not necessarily the calendar. The new stem can grow 15 to 20 feet in one season!
Dioscorea mexicana’s flowers bloom in late summer.
Dioscorea mexicana is dioecious meaning that the individual plants in the species are either male or female. The leaves are glossy green and heart-shaped. Flowers are greenish with dark purple centers and bloom in late summer. Although considered inconspicuous, I feel the male flowers add some visual interest. The caudex requires shade, usually provided by surrounding vegetation, while the vining portion of the plant needs full sun. It prefers to grow in a well-drained soil. Dioscorea mexicana is mostly propagated by seed, but although stubborn can be grown from cuttings.
If you can find one, this plant will have even the best plant enthusiasts talking and asking questions. Its easy winter care regimen (in most years) makes it a great choice for an exotic tropical look. During winter months greatly reduce the amount of water given to the plant; a light monthly watering is needed at most. I couldn’t find much information about and personally don’t know its hardiness but wouldn’t expose it to temps much below freezing for extended periods of time. Slowly bring it out of dormancy in the spring and give it lots of water during the hot growing summer season. Despite being nicknamed after a slow mover, Dioscorea mexicana quickly proves itself a crowd pleaser!
-Matt Fleming, Horticulturist
Smithsonian Gardens presenta Las Orquídeas de Latinoamérica
Oncidium Red Stars ‘Rooster’
La Institución de Smithsonian tiene una larga historia de la recolección de plantas para compartir su belleza con el mundo. ‘Smithsonian Gardens’ sigue compartiendo esta tradición a través de su colección de orquídeas. Esta colección ha aumentado desde 1974 cuando adquirieron las primeras cinco plantas. Desde entonces, la colección de orquídeas ha florecido enormemente y hoy tenemos a más de 8,000 especies en nuestro invernadero.
Las plantas que forman esta colección son utilizadas para elevar la belleza y la maravilla de los museos Smithsonian. Cada año podemos disfrutar la gran variedad de sus brillantes colores y formas cuando muestran sus encantadoras flores. Aprovechen y celebren estas maravillosas plantas cuando visiten a los museos Smithsonian. Podrán ver orquídeas que representan a países tan lejanos como China o más cercanos como nuestros vecinos de México. La exposición este año celebran Las Orquídeas de Latinoamérica. Visiten y admiren las bellas flores exóticas que tenemos en exhibición en el Museo Nacional de Historia Natural y reciban más información y detalles que les ofrecemos en español e inglés.
- Sarah Mirabal, Orchid Intern
Victorian Love of Nature, Ornament and Decoration on Display
OH.1985.32, Plant Stand, c. 1850-1900, Cast-iron, 44” x 25.5”
Plant stands such as this, from the Smithsonian Gardens’ Garden Furnishings and Horticultural Artifacts Collection, were the perfect tool to combine a love of nature with a taste for ornament and decoration in the Victorian Era. Named for Queen Victoria of Great Britain, the Victorian Era classifies the period of society and the fine and applied arts during her reign from 1837 to 1901.The cultivation of plants was a widely popular pastime for the Victorians in all levels of society, and their toils were proudly displayed in homes and gardens. Plant stands became an essential item for the exhibit and storage of flowers and foliage. Their practical and decorative benefits were amplified by the link they provided between the domestic interior and the natural world that had gone missing due to the Industrial Revolution.
Plant stands were manufactured in England, America, and France, and came in a variety of forms and materials. Cast- and wrought-iron were the most common materials for garden ornaments such as this; however, they also came in wood, wicker, glass, and ceramic versions and were usually painted white, black, brown, or green. Circular, semi-circular, or squared structures could be positioned against a wall or in the center of a space. Single level and tiered versions were popular, in addition to the plant stand we see here that has multiple appendages.
This type of plant stand was made using separately cast arms attached to a central axis rod. The arms could be rotated and moved vertically along the pole to display plant specimens of various sizes. The cup at the end of each arm would hold a small flower or foliate, which were often in their own removable liner so they could be changed out seasonally.
Plant stands are still a popular indoor and outdoor garden accessory for displaying plants. Just as they did during the Victorian Era, they showcase a selection of seasonal varieties to beautify the home and bring nature within reach.
Further Reading:
Israel, Barbara. Antique Garden Ornament: Two Centuries of American Taste. New York: Harry N. Abrams, Inc., 1999.
-Janie R Askew
Research Assistant, Smithsonian Gardens
MA Candidate, History of Decorative Arts
The Smithsonian Associates/George Mason University
Outstanding in the Field
On October 1st, Smithsonian Gardens’ Victory Garden at the National Museum of American History (NMAH) was the pre-dinner reception site for attendees to an Outstanding in the Field (OITF) event which benefited NMAH’s upcoming exhibit, Food: Transforming the American Table, 1950-2000.
Joe Brunetti of Smithsonian Gardens gave opening remarks and was ‘Host Farmer’ for the program. Organic produce from the Victory Garden was provided to the OITF chef to use in the main event, dinner on NMAH’s rooftop. Joe and his SG colleague Erin Clark gave tours of the Victory Garden and answered gardening questions from some of the 150 attendees. Outstanding in the Field’s mission is to re-connect diners to the land and the origins of their food, and to honor the local farmers and food artisans who cultivate it.
The beauty of this event went beyond just lapping up the good food. Some of the magic arose from the conversations with complete strangers, the handshakes welcoming each other, and the cohesive celebration for the nourishment on the table. Even though attendees came from all parts of the country, we were all coming together with the same passion for land, food and drink. This movement of reconnecting to our land is happening on many different fronts. People are interested in where their food is coming from, how it is being grown, and who it is supporting. It seems a simple idea, but an idea we have removed ourselves so far from. With the increasing number of farmers’ markets and the re-evolving lifestyle of being a locavore, we can hold our glass up high and say ‘cheers.’
In the words of Julia Child, ‘Bon appétit’!
-Joe Brunetti, Horticulturist, Victory Heirloom Gardens at the National Museum of American History
Hellebores: Jewels of Winter, Part II
Last week Smithsonian gardens Horticulturist Janet Draper introduced us to some of the most beautiful of the winter flowering plants, Hellebores. Here are a few more of her favorite picks for your home garden:
Helleborus niger
One of the new cultivars that I have been most impressed with are new varieties of Helleborus niger, a.k.a the ‘Christmas Rose.’ I had never been impressed with Helleborus niger in the past, but the selection ‘Joseph Lemper’ has really changed my opinion. It is marketed as part of the Helleborus Gold Collection (HGC) from Heuger nurseries in Germany. The Joseph Lemper in the Ripley Garden started producing numerous 2-2 1/2” flowers on sturdy tall stems held well above the foliage in late NOVEMBER and it is still producing new flowers in late February! I am not sure if this form is sterile or not, but either way this cultivar is a showstopper for the winter garden.
Helleborus x ballardie ‘Pink Frost’
Helleborus x ballardiae ‘Pink Frost’
Another member of the HGC series is Helleborus x ballardiae ‘Pink Frost’. This beauty starts blooming in February and will continue for at least a month. It has lovely upward-facing pink flowers which turn a deeper shade of pink as they age. The foliage is gorgeous, with lovely white veining and red stems. My plants are still young, but I am really impressed with what is showing so far!
There are many other exciting new cultivars hitting the market, including some from local breeders like David Culp in Pennsylvania, Barry Glick in West Virginia and Judith and Dick Tyler in Southern Virginia. There are new selections which are double flowered, or possess dramatic markings, enlarged nectarines, upward facing flowers… oh the madness!
I have been slowly adding more and more of these winter gems to the Ripley Garden and currently have nineteen different varieties. Some are still quite small and will not bloom for a year or two since they take some time to get established, but all are worth the investment of time and money to brighten your winter garden.
-Janet Draper, Horticulturist
Smithsonian Gardens Greenhouses Welcome Bluebirds
The installed nesting boxes on the Eastern Bluebird Habitat Trail.
Working in collaboration with Richard E. Gies, lead volunteer of the Longwood Gardens Bluebird Project, Smithsonian Gardens established an Eastern Bluebird Habitat trail around the perimeter of the Greenhouse facility in Suitland MD.
Eastern Bluebird. Photo Courtesy of U.S. Fish and Wildlife Service. Dave Menke, photographer.
Why Bluebirds?
A native songbird, the Eastern Bluebird (Sialia sialis) is a member of the thrush family (Turdidae). They eat insects and berries and require open grassy areas and meadows with low groundcover for feeding. These beautiful birds breed in all eastern states from Maine to Florida. They are considered to be secondary cavity nesters in that they traditionally nest in holes made by woodpeckers and other birds.
The nesting boxes were installed to benefit an existing population of Bluebirds as well as to encourage more bluebirds to nest on site. Eastern Bluebird populations are on the rise thanks, in part, to efforts like this one. The lack of suitable nesting cavities caused by changing land use patterns, increasing urbanization, and competition from introduced European starlings and house sparrows has been responsible for the decline of Eastern Bluebirds populations in the past.
Tree Swallow. Image courtesy of the U.S. Fish and Wildlife Service. James C. Leupold, photographer.
When is a pair of nesting boxes better than one?
In areas where Eastern Bluebirds coexist with Tree Swallows (like Maryland) it is recommended that two boxes be placed 15-20 feet apart. Tree swallows will select one box for nesting and defend the other against use by other swallows thereby allowing Bluebirds to claim it.
Green roof nesting boxes waiting to be installed at the Smithsonian Gardens greenhouses in Suitland, Maryland earlier this winter.
A Green Roof: for style and comfort.
The roofs on these nesting boxes have been planted with a variety of stonecrop (sedum) plants. The purpose of the “green roof” is to help keep the interior of the boxes cool during the hot summer months.
The temperature inside these nesting boxes will be monitored in an effort to ensure the safety of the fledglings (baby birds).
The green roof nesting boxes were designed Richard Gies for Longwood Gardens. You can download a PDF of his instructions here:
Hellebores: Jewels of Winter, Part I
Most people think that winter is a “dead time” in the garden, but they could not be more wrong. In a climate as mild as Washington DC (officially a zone 7b, but Mother Nature doesn’t seem to like being pigeonholed), little signs of spring start to appear as early as January.
I’d like to share my love affair with the jewels of the winter—Helleborus. Hellebores are members of the Buttercup family (Ranunculaceae), and are shade loving, evergreen plants which bloom during the winter months. Wait—it gets even better—deer don’t find them to be particularly tasty!
It used to be that the most commonly found hellebores in nurseries were the Christmas rose, (Helleborus niger) and the Lenten rose (Helleborus hybridus). Other species were available but sorely under appreciated Times have changed, and thanks to breeders, the diversity of Hellebores on the market is quite amazing,
Here are a few of my favorite Hellebores growing in the Smithsonian Mary Livingston Ripley Garden:
Helleborus foetidus
A long time favorite of mine has always been Helleborus foetidus, or the Stinking Hellebore. What a cruel name for a gorgeous plant! Helleborus foetidus has finely-cut fingerlike evergreen foliage which thrives in shady conditions. The real show begins in October when chartreuse flower stalks start emerging above the foliage, taunting you with the promise of flowers. The small lime green bells finally unfurl in late January or February, demure clusters of little green bells edged in raspberry.
One interesting fact about Hellebores is that the flower ‘petals’ are actually modified leaves so even after the flower starts seed production, these ‘petals’ remain attractive for two to three months.
The only maintenance required for this hellebore is to cutting off the flower stems once they start to look tatty. Or, if you have enough plants, cut off the flowering stems before the seed pods ripen, otherwise they will self sow to produce a large colony.
Helleborus argutifolis, ‘Corsican Hellebore’
Helleborus argutifolius
Another favorite species of mine is Helleborus argutifolius, or the Corsican hellebore. It also produces lovely chartreuse flowers, which are striking against its coarsely-toothed blue-grey foliage. The flower opens entirely and is outward facing to display the prominent yellow stamens very clearly. The one challenge I have with the Corsican Hellebore is that the two-foot stems flop, leaving a gaping bald spot in the center of the clump—nothing a little discrete staking can’t hide. Like Helleborus foetidus, the Corsican hellebore is caulescent (flowers are produced on the same stem as the foliage) so once the flowers begin to look tatty or you don’t want any more plants, remove this entire stem down to the ground, and any other stems that look rough after the winter.
Hellebore x hybridus, ‘Lenten Rose’
Helleborus x hybridus
One of the classic hellebores on the market is Helleborus x hybridus, the Lenten rose, with blooms ranging from white to pink. Due to the seed grown variability it is always best to purchase plants in flower if you want to know what you’re getting. Otherwise, enjoy the surprise!
-Janet Draper, Horticulturist
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