Posts filed under ‘Horticulture’
One of the most glorious harbingers of spring, Hamamelis x intermedia ‘Arnold Promise’ is in full glorious bloom in the Mary Livingston Ripley Garden. The blooming of the Witch hazels is a sure sign that the end of this dreadful winter is near.
You cannot miss these beauties—they are often referred to as trees, but in actuality they are mature shrubs. The specimens in the Ripley Garden are probably over forty years old and are about twelve feet tall and fifteen feet wide and covered in small golden spider-like flowers. What I find so magical is that the flowers will curl the petals up on a cold day and unfurl once again when the sun hits them. Although they look dainty, they are built for cold temperatures. I have often seen them blooming while covered in snow.
Oh, and did I mention the fragrance? Exquisite, dreamy sweetness. The entire south end of the garden is perfumed.
Also in bloom, but a little more subtle:
-A couple of newly-planted Adonis amurensis have recently bloomed. Golden two-inch flowers peak out just above the soil on naked stems. After the flowers start fading the lacy foliage will emerge for a few months then go dormant in the summer.
-Dainty little yellow Eranthus hyemalis—this ground-hugging Winter aconite looks like little yellow bubbles above a ruff of foliage. The “bubbles” are actually the five-petaled flowers curled up before they fully open.
-The first signs of Daffodil ‘Rinjvelt’s Early Sensation’ –not a prize daffodil, but one of the earliest, so thus it is very special to me!
-And a few Crocus tommasinianus, the sweet, self-sowing, little ‘Tommy Crocus’ which I have planted under a mature Harry Lauder’s walking stick (Corylus avellana).
Come on out – I am sure every day something new will be emerging from a snowy slumber. We will post more photos of the Ripley Garden soon.
-Janet Draper, Smithsonian Gardens horticulturist
Did I jinx myself by saying that I had seen the Witch hazel in the snow? Guess what is happening in Washington, D.C. right now?. Yep, More snow. YUCK. (But, I must confess, right now it is pretty magical out there.)
Just of few things that caught my eye:
In the summer of 2013 a specimen lacebark pine (Pinus bungeana) at the National Museum of Natural History had been in decline for several months. An investigation by Greg Huse, Smithsonian Gardens arborist, found very large girdling roots growing just below the soil surface. In his report Lacebark Pine # 122 Evaluation at NMNH he determined there was little to no chance that the tree could be rehabilitated. Within two months of issuing the report the tree turned completely brown and it was clear that it need to be removed.
Or did it? Could the once stately pine on the corner of Madison Drive and 9th Street that formed the border between the Butterfly Habitat Garden and the newly established Urban Bird Habitat find a second life?
As a mature specimen of this slow growing pine the tree exhibited extraordinary exfoliating bark in a patchwork of white, olive, light purple and silver. The multi-stemmed trunk was a striking structural element in the landscape that would be a significant loss. Luckily, there was a way to save this feature and in doing so support wildlife enhancing the value and educational lesson of the space. The tree was the perfect candidate to become a snag.
By turning the soon to be rotting trunk and branches into a snag it gains a new purpose in the Urban Bird Habitat serving as a space for nests, nurseries, storage, foraging, roosting and perching for birds, small mammals, and other wildlife in the city.
Here is how we did it:
The garden is a dynamic landscape and one must be prepared to deal with the changes that nature brings. Through creative thinking the Smithsonian Gardens’ staff discovered a great opportunity to turn what could have been a significant loss to gardens into a valuable resource. Today many museum visitors stop to look at this unique tree along the National Mall. Most seems puzzled by its presence but their questions are answered by the Snag interpretive panel.
So what do you think? Does your garden have a spot for a snag? Please share your thoughts in the comments below.
-James Gagliardi, Smithsonian Gardens Horticulturist
Living with Wildlife: Snags – The Wildlife Tree from the Washington Department of Fish and Wildlife.
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.
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:
-Shelley Gaskins, Smithsonian Gardens Horticulturist, Green Team Member
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?
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.
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
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.
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.
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.Seedheads create interest with varying shapes and textures and make a dynamic feature in winter as they mature and disperse.
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.
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.
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.
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.
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
Most of us begin to think about holiday decorations as it gets closer to Thanksgiving. This is not the case for our Smithsonian Gardens Interiors staff! As soon as the holiday decorations are taken down in January, we’re already making plans for next year’s holiday decorations.
Poinsettia types and numbers have to be decided on by April so that the orders can be placed. Tree, wreath, and garland decorations have to be determined by May so that those supplies can be purchased. The poinsettia plugs arrive and are planted in July (taking a full 4-5 months for us to finish, the poinsettias are our longest growing annual crop in the greenhouse). Only a couple of the holiday trees on display are artificial, but the rest are real and are selected especially for us, coming from a tree farm in Pennsylvania. Sometimes our staff even travels to hand pick the trees.
Next there’s the holiday prep: all of the tags have to be removed from each of the new ornaments, wire hangers need to be attached, some decorations need to be assembled and wired together, bows need to be made, and wreaths and garland need to be decorated.
Some of this prep work starts as early as October. Then there’s the planning, which involves deciding which day to install the decorations, and coordinating with each of the museums to make sure that we will not interfere with what is going on in the museums on that particular day.
Our first tree, the Castle Tree, was installed the week of Thanksgiving. The rest of the decorations will be up this week.
Please take some time to walk around and visit each of our museums and appreciate all of the hard work and planning that goes into the holiday decorations. All of this work would not be possible without the help of our volunteers and other Smithsonian Gardens staff who help with prepping the décor and decorating the trees.
-Alexandra Thompson & Shannon Hill
Happy Holidays from the Smithsonian Gardens Staff!
Smithsonian Gardens’ Green Team had a unique opportunity to visit the Blue Plains Advanced Wastewater Treatment Plant (AWTP) owned and operated by Washington, D.C.’s Water and Sewer Authority or DC Water. Serving the District and nearby suburbs, the plant takes in more than 330 million gallons of raw sewage daily.
We had the pleasure of meeting with General Manager George Hawkins before getting a tour of the facility. After just a few minutes spent with Mr. Hawkins you could immediately appreciate not only his vast knowledge but his passion for what he does. He touched upon several aspects of DC Water, from its many large construction projects to its water treatment process to sustainability.
The Washington Aqueduct provides the public water supply system serving Washington, D.C., and parts of nearby suburbs and is run by the U.S. Army Corps of Engineers. DC Water takes wastewater and runs it through cleaning processes using mechanical, chemical and biological methods like screening, aeration, polymer use and bacterial digestion. Once cleaned to EPA standards, this treated water is then put back into the Potomac River and the cycle begins once again.
One way DC Water is becoming more sustainable is with a huge construction project to further the biosolids management program with a Thermal Hydrolysis Process (THP) and digestion facility. Once completed, the project will not only be the largest of its kind in the world, but also save DC Water around $10 million a year in energy costs and cut its usage by a third. (DC Water is currently the largest consumer of electricity in the District.) It will also reduce the amount of carbon emissions by approximately 50,000 metric tons yearly. DC Water hopes to have the process up and running by July 2014.
George Hawkins actively looks for ways for DC Water to be more sustainable instead of simply taking the tried and true (easier) way out. Currently, any excess water generated during a large rain event that the facility can’t handle overflows into the city’s rivers. DC Water’s Clean Rivers Project is a colossal undertaking that will help alleviate that issue; a huge cistern-like cavity is currently being built to gradually treat storm-water that overwhelms the system. George also sees other ways of dealing with excess water, such as a push for individuals and the government on all levels to build bioswales, green roofs and rain gardens to help mitigate the problem.
One way the public can help be more water smart is by drinking more tap water instead of using bottled water. To this end, DC Water is directly involved with a project called TapIt that is also found in other cities. TapIt enables you to locate eateries (via internet search, iPhone app, or restaurants labeled with a TapIt sticker) that will let you bring your own water bottle and fill it for free.
DC Water hopes someday to become net zero for energy consumption meaning it would produce energy equal to or more than its daily needs. With future plans to double the Thermal Hydrolysis Process and digestion facility and talks of installing solar panels, DC Water thinks it can achieve this lofty goal. If everyone uses water more consciously and tries to alleviate polluting through trash and water runoff we can make D.C.’s rivers a major highlight of the city.
-Matt Fleming, Smithsonian Gardens Horticulturist
Now that tomatoes have lost their summer pizzazz it is time to look to other fresh vegetables to punch up salads. Tossing winter squash with greens may seem odd, but when the squash is roasted, it adds sweetness to salads similar to fresh fruits. Chopped pears add another layer of sweetness and make the salad juicier. Pomegranate seeds and walnuts add crunch; cayenne pepper is necessary to balance their sweetness.
Peeling winter squash so it can be cubed and roasted is always a bit of a challenge. Smooth-skinned butternut squashes are so appealing to cooks because they are easy to peel with a vegetable peeler. But don’t let ribbed, bumpy and warty skins thwart experimenting with other squashes. Relax and take the time to carefully peel the tough skin. A vegetable peeler is still the best tool; you may have to cut the squash into smaller, more maneuverable pieces to remove the skin from all the nooks and crannies. The abundance of varying flavors is worth the effort.
Don’t take the easy way out and just cut the squash in half and roast it. Cubed, roasted squash can be used in so many different recipes: tossed with pasta, sage, garlic and parmesan cheese; sautéed with onion and served as a winter bruschetta; or combined with pancetta, rosemary and ricotta cheese and used as a pizza topping.
Roasted winter squash makes saying goodbye to summer a little easier! This fresh salad is a perfect way to celebrate the harvest on Thanksgiving.
Autumn Farmer’s Market Salad
Adapted from a recipe in Bon Appetit October 2008
Makes 6 servings
4 1/2 to 5 cups, 1/2-inch cubes of peeled and seeded winter squash (about 2 pounds, I used Tetsukabuto and Honey Bear Squash, both are orange-fleshed moist squashes.)
2 tablespoons extra-virgin olive oil
¼ teaspoon cayenne red pepper
¼ teaspoon salt
2 tablespoons orange juice
3 tablespoons walnut oil
1 1/2 teaspoons fresh lemon juice
1 bunch arugula (about 6 cups), torn into pieces
1 small head Bibb lettuce (about 4 cups), torn into small pieces
2 Bosc pears, cores removed; cut into bite-size pieces (to prevent browning, put pears in lemon water until it is time to construct the salad)
1/2 cup walnuts, toasted, coarsely chopped
1/2 cup pomegranate seeds
2 teaspoons pomegranate molasses*
Preheat oven to 450°F. Toss squash, olive oil, and cayenne pepper on large rimmed baking sheet. Sprinkle with coarse salt. Roast 15 minutes. Using spatula, turn squash over. Roast until edges are browned and squash is tender, about 15 minutes longer. Sprinkle with coarse salt and let stand at room temperature while making the salad dressing and putting the greens together.
Whisk orange juice, walnut oil, and lemon juice in large shallow bowl. Season to taste with salt and coarsely ground pepper. Add arugula, Bibb lettuce, pear, walnuts, and pomegranate seeds; toss to coat. Season greens to taste with coarse salt and pepper and then add cooked squash. Drizzle with pomegranate molasses and serve.
* I found the pomegranate molasses at Whole Foods, but it can also be found at groceries specializing in Middle Eastern cookery.
-Cindy Brown, Manager, Horticulture Collections Management and Education
As Abraham Lincoln once said, “We cannot consecrate-we cannot hallow-this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract.” In honor of Veterans Day in 2010, Brian Thacker, a recipient of the Congressional Medal of Honor was joined by representatives from the Medal of Honor Foundation, the National Air and Space Museum, and many veteran Smithsonian staff and volunteers to dedicate The Medal of Honor Tree on the grounds of the National Museum of American History (NMAH). Traditionally, red oaks (Quercus rubra) lined the north side of the museum. However, over time many of these trees were lost. To fill in the spaces left by the missing trees, Smithsonian Gardens collected trees from placed of historic significance to the United States such as the Lexington Green, the Trail of Tears, and the Manassas Battlefield. Brett McNish, Supervisory Horticulturist with Smithsonian Gardens, originally had the idea to seek out these historic trees and in conversation with a close friend in the museum community came up with the idea for the Medal of Honor Tree.
The tree commemorates recipients of the Congressional Medal of Honor. This award was created on July 12, 1862 when the bill S.J.R. No. 82 was signed into law by President Lincoln. The law designated that Medals of Honor were to be “presented, in the name of Congress, to such non-commissioned officers and privates as shall most distinguish themselves by their gallantry in action, and other soldier-like qualities.” Following the establishment of the Medal of Honor, soldiers quickly began receiving the medals for their valiant efforts in battle. The largest number of Medal of Honor recipients in one day of battle (120) took place at the Battle of Vicksburg on May 22, 1863. Since its creation, 3,463 service men and women have received the Medal of Honor. A variety of individuals have received the Medal of Honor representing the complex fabric of our nation. Medal of Honor recipients include one woman (Mary Walker), eighty-seven African Americans, forty-one Hispanic-Americans, thirty-three Asian-Americans, and thirty-two American Indians. Since 1918, Medals of Honor can only be given to members of the U.S. Armed Forces. However, exceptions have been made in special circumstances. Sixty-one Canadians, for example, hold the Medal of Honor, many of them from actions in the American Civil War. While the Medal of Honor now must be given to a member of the U.S. Armed Forces, they do not have to be U.S. citizens. The most recent Medal of Honor was awarded to Captain William D. Swenson on October 15, 2013.
To dedicate the Medal of Honor Tree, consecrated ground from 16 battlefields relating to 11 different wars that the United States was involved in were collected and added to the soil at the base of the tree. McNish discussed the immense task of collecting soil samples from these battlefields: “My goal was to get at least one soil sample from every war the US fought. Then it came down to what was possible to obtain. I think I came close to getting most of them. It took me about six months to get everything.” The process of collecting the soil involved many helping hands from the USDA, Department of State, Department of Defense, the American Battle Monuments Commission, and others, along with “a hefty FedEx bill” McNish noted. He created little collection kits made out of heat-resistant plastic containers.
A number of interesting stories grew out of the soil collection project. The soil collected from Luxembourg was from General George Patton’s grave at the Luxembourg American Cemetery and Memorial. The soil from Iwo Jima had its own history; it had been previously been collected by a Marine who visited the island on a pilgrimage. The soil then made its way to numerous veterans who took a little of it for themselves. McNish received the remaining soil from a retired Air Force officer in an airport VIP lounge. Then U.S. Ambassador to the Republic of Korea, Honorable Kathleen Stephens, collected Korean War soil from the Pusan Perimeter, an area that witnessed some of the first fighting of the Korean War. Soil from Haiti was collected by a group of Smithsonian curators working on post-earthquake relief for Musée National d’Haiti (the National Museum of Haiti). Because of difficulties mail, obtaining soil from Afghanistan was very difficult. The soil went through numerous hands before it was finally spread under the tree by an SI employee who had just returned from a tour of duty in Afghanistan.
Since its planting in 2010, the Medal of Honor Tree at NMAH is decorated every Veterans Dhistoay with a large red, white, and blue ribbon with a yellow center to highlight its significance in remembering the sacrifices of our nation’s service men and women.
-Mattea Sanders, Smithsonian Gardens intern
When people walk through the landscapes of Smithsonian Gardens, they often take pleasure in the beauty and majesty of the trees that are found throughout. The large spreading canopies, colorful spring and summer blooms, and brilliant autumn colors make for a feast for the eyes. Although we take great pride in the appearance of the trees here at Smithsonian Gardens, we also manage them for the numerous benefits that they provide, many of which are often not recognized.
Urban trees provide myriad contributions to the areas where they grow. Some of those benefits include:
- Storm water runoff and flooding reduction. It has been found that trees absorb the first 30% of most precipitation events through their leaf systems, and up to another 30% can be absorbed and held by their root systems.
- Traffic calming. Research shows that tree lined streets have fewer and less severe traffic accidents than those with no trees.
- Reduction of air pollution. Tree crowns capture and trap air pollutants, including automobile exhaust gasses and particulate matter. The severity of asthma and other negative health impacts are reduced in the presence of trees.
- Carbon sequestration. Trees absorb and retain carbon, thereby contributing to the reduction of greenhouse gasses. A US Forest Service study found that the average annual carbon sequestration of urban areas in the U.S. is approximately 26 million tons totaling a $2 billion value.
- Lowering of air temperatures. Urban areas can become extremely hot, as all of the concrete, asphalt and other hardscapes absorb heat throughout the day. In areas with trees, air temperatures can be reduced by 3-10°F, and properly shaded neighborhoods can realize energy cost savings of up to 35%.
- Improve your health. The findings of one study show that areas that have many trees can lower blood pressure, have a calming effect on teens and adults with ADHD, and contribute to overall emotional and psychological health.
- Add to property values. Realtor based estimates of street tree versus non-street tree comparable streets show a $15,000-$20,000 increase in home or business value.
So, the next time you’re enjoying the trees here at Smithsonian Gardens, remember all of the wonderful and helpful things they’re doing for us!
-Greg Huse, Smithsonian Gardens Arborist and Tree Collection Manager