Posts filed under ‘Horticulture’
At the end of April, after ten months of planning, coordinating, and troubleshooting, the Smithsonian Gardens Orchid Collection (SGOC) went live. No, we didn’t kill off all of the plants over the winter and revive them for this announcement . . . I mean live as in on-air, online, and freely accessible! SGOC is now available for the world to explore on the Smithsonian Collections Search Center and is the only living collection to join the multitudes of objects, specimens, and archival records that are contained within the site. Below is a snapshot of what an individual catalog record looks like:
Records are updated twice a month and contain basic information about each accession, such as scientific name, flower color, range (if a species), and taxonomy. One of the best parts of having the collection online is being able to peruse the beautiful images taken by our talented volunteers Gene Cross, Bryan Ramsay, and James Osen. So far, about a third of the records have images associated with them. We only photograph the orchids when they are in bloom, but many of our orchids (especially the species) are either too small to bloom, or haven’t yet bloomed during their time at the greenhouses.
SGOC’s presence on the Collections Search Center is serving as motivation to improve Smithsonian Gardens’ collection records in BG-BASE and correct plant identification errors. Our hope is that these records can be a valuable resource for educators, students, researchers, and curious individuals, and a source of orchid inspiration year-round.
-Julie Rotramel, Smithsonian Gardens Living Collections Contractor
The common name rain lily comes from this plant’s tendency to bloom after a good soaking from Mother Nature. They are native to tropical and semi-tropical regions of the Americas. There are 3 genera commonly known as rain lilies – Zephyranthes, Habranthus, and Cooperia. Rain lilies are a perennial bulb with a hardiness of USDA Zones 7 to 11 for most species. They come in various colors, mostly ranging from pinks, yellows, and whites and new colors are popping up through hybridizing and breeding all the time. Although the common name would suggest that they are in the Liliaceae (lily) family, they actually fall under Amaryllidaceae.
Rain lilies are often grown in containers where they can be placed on a front porch or around a deck and will reward all season long. I have found that if grown in containers, they seem to prefer being slightly crowded and even somewhat pot-bound. They also look great along a pathway or in the front of a sunny border and are often used in rock gardens. To get the finest show, Rain lilies look best planted in masses. Most Rain lilies will bloom several times a season, usually after a good downpour.
If you live in a zone where Rain lilies are not hardy they are easy to overwinter. When it starts getting cooler, simply bring them indoors (either the container or, if planted, the dug up plants – if possible give them a quick potting) and keep them dry all winter, then set them outside again in the spring. You can pull off the foliage as it dies to keep them clean. You may want to either add soil or rough the edges of the pot prior to setting them outside if the soil has shrunk over the winter.
Rain lilies grow best in full sun to partial shade. They prefer to be kept evenly moist but can tolerate periodic dry spells without problem. During summer months use a well-balanced fertilizer (either liquid or slow release). The bulbs produce offsets which can be divided and planted in spring or you can sow seeds if you wish. If you are collecting seeds, sow right away before they dry as they tend to lose the ability to germinate and may take extra time to do so. Rain lilies are very gardener-friendly as they have no serious pest or disease issues. I have had problems with mealy bugs, however, but that is because I start watering them earlier in the season than normal and I keep them in the greenhouse for a fuller plant come spring. Be aware that all parts of the plant can be toxic if ingested.
After reading this, you may be eager to see some Rain lilies for yourself, so please stop by the Ripley Garden at the Smithsonian Institution this summer and enjoy their beauty. Some of the ones we display are Zephyranthes flavissima, Habranthus robustus ‘Russell Manning’, Habranthus texanus, and Zephyranthes candida.
-Matt Fleming, Smithsonian Gardens horticulturist
Join us this Saturday, May 9th, from 10 a.m. to 3 p.m for a celebration of “Water, Water, Everywhere” at Garden Fest in the Enid A. Haupt Garden. In this blog entry Sarah Tietbohl writes about just one of the many ways we try to conserve water at Smithsonian Gardens.
When I first started at Smithsonian Gardens in 2010 I was assigned the job of cleaning the Moongate fountain in the Enid A. Haupt Garden. I was excited about this task as I would have an opportunity to learn to use a new piece of equipment and keep cool during the hot summer months. I estimated that the fountain would need to be cleaned maybe once a month. With the pond open between April and October, that would total seven times a year. That spring, the cleaning schedule started out at once a month. As the season went on and the temperatures climbed into the 90s, I noticed that the fountain was growing algae at a rapid pace. It turned the water a sickly slimy-green color. That once-a-month cleaning turned into scouring once or twice a week! That season, I ended up cleaning the fountain well over twenty times. The next year it was the same story.
After the summer of 2011, I really started to think about all of the water, energy, and time it takes to clean the Moongate fountain. I started to gauge the amount of water that was being used in one year to clean and fill the fountain. I calculated that it takes 2,300 gallons of water just to fill the fountain each time it is cleaned, plus 200 gallons or so to clean it. I decided to research environmentally-friendly products that would reduce the amount of algal growth, thereby cutting down on the amount of water needed to re-fill the fountain after each cleaning. Fewer cleaning sessions would also result in less emissions (and noise) generated from the power washer that runs every time the fountain is cleaned. I started experimenting with a non-toxic black pond dye. Adding black dye to the fountain reduced the amount of sunlight that was able to penetrate the water, which in turn reduced the algal growth. I found the dye to be very effective and talked my colleagues into using it in the fountains in the Ripley and Folger Gardens as well. Thanks to the black dye solution, Smithsonian Gardens has reduced fountain water use from 60,000 gallons a year to slightly less than 22,000 gallons- a terrific way for Smithsonian Gardens to employ a sustainable alternative in its operations.
-Sarah Tietbohl, Smithsonian Gardens
Container gardening is fun for everyone and easier than most people think. Containers are easier to maintain in areas where space is limited, easy to move around depending on the light requirements, can be rotated depending on the season, and will break up the monotony of a deck, patio, or terrace.
It is entirely up to you, the gardener, whether to select the container before or after the plants are chosen. Just make sure the plants and the container complement each other in size and color and remember that drainage in the container is a must!
Container gardens require a soil mix that is light and well drained. Many potting mixes also have fertilizer added and contain ingredients to help retain moisture, both of which are helpful for container plants. It is best to purchase soil labeled exclusively for container gardening. These mixtures are usually made from ingredients that—oddly enough—don’t include soil, thereby making them “soilless” mixes. If you find the bag too heavy to pick up it’s probably too heavy to use in a container.
Plants with the same growing conditions and water and light requirements should be planted together. Consider using non-flowering plants for unique leaf texture and color along with flowering plants, perennials, herbs, and even vegetables. This type of planting is called “fusion” gardening in the green industry. Perennials used in containers during the season can then be planted in the garden bed for the following year.
For a great looking display, a mixture of tall, medium-sized, and trailing plants is important. Tall plants can be planted in the center, off to the side, or at the back of the pot. Shorter plants can be placed around the tall plants and trailing plants close to the outside edges.
The plants will only receive nutrition from you so using a well balanced fertilizer is important for overall plant health. Top dressing with a slow release fertilizer helps get the plants off to a good start. The more water you add to the soil, the more fertilizer the plants will need. An all-purpose food mixed with water is an easy and fast way to feed your plants.
A daily watering check is a must, especially if the container is displayed in full sun during the summer months. Watering in the morning is best. Plants will be able to quench their thirst through the warmer parts of the day and the risk of foliar diseases will decrease if the leaves are kept dry in the cooler temperatures at the end of the day.
Many varieties of plants need to be deadheaded to remove spent flowers and encourage more branching and new flowers. Routine maintenance will also alert you to any diseases or pest problems that may occur in the container garden.
Inspire yourself to bring color and excitement to every area around your home through the wonderful world of container gardening. Start out small and simple. Gardening is a perfect way to achieve some quiet time and interact with nature. Discover how fulfilling and fun container gardening really can be!
-Jill Gonzalez, Smithsonian Gardens Horticulturist
It’s April Fool’s Day! You know what that means . . . Don’t worry, we don’t have any tricks up our sleeves today. We’re going to let the plants pull all the pranks. We asked Smithsonian Gardens horticulturists to think of a few of their favorite plants that deceive and mislead both pollinators and gardeners alike. (Yes, we are anthropomorphizing here; guilty as charged!)
Tom Mirenda, Smithsonian Gardens orchid specialist and horticulturist, had many suggestions! Orchids are masters of trickery and deception.
Smithsonian Gardens manages the health and maintenance of 1,873 trees in the Washington, D.C. area. As you walk around the Smithsonian gardens and museums you may notice a common theme: many of these trees are mature specimens with historical context and connection to the museums they surround. This is extremely evident as you walk the grounds of the National Museum of Natural History, where the extensive American elm plantings bring us back to a time when Ulmus americana was the predominant street tree in America. In fact, the large specimen on the corner of 9th Street and Constitution Avenue predates the museum, which celebrated its centennial in 2010.
As Dutch Elm Disease (DED) has wiped out the majority of stately American elms throughout the U.S., we at Smithsonian Gardens work diligently to monitor and manage our trees in order to prevent the spread of this lethal disease.
It is with this management strategy in mind that we carefully select replacements when elm trees at the Smithsonian need to be removed. When one of the younger elms on the north lawn of the National Museum of Natural History was critically damaged during a storm, we once again debated and discussed which “resistant” elm to replace it with. One of the best choices for a true Ulmus americana replacement is the ‘Jefferson’ Elm (Ulmus americana ‘Jefferson’), selected through the collaborative efforts of the National Park Service and the USDA’s Agricultural Research Service (ARS).
This tree was selected for its excellent DED resistance and the fact that as a true species, it exhibits the classic American elm form, unlike some of the resistant hybrids.
‘Jefferson’ elms leaf out earlier in the spring and maintain their green color better in the summer than other U. americana specimens. We were very lucky to receive this tree from the National Park Service as it is just becoming available in the commercial trade at this time, and can be difficult to find. The National Park Service propagates ‘Jefferson’ by cuttings from the original tree, located on the National Mall, and grows the seedlings for six years at its National Capital Region Nursery. It is a long process and a difficult one, as only about 5% of the cuttings live to become mature trees. Hopefully this selection will become more common in the nursery trade so that we can once again plant these majestic trees with confidence. Until that time, we are very thankful for the ongoing collaboration between the National Park Service and Smithsonian Gardens to ensure that the American elm still graces the Washington, D.C. landscape.
-Jonathan Kavalier, Smithsonian Gardens Supervisory Horticulturist
Anyone who’s seen specimens from the Smithsonian Orchid Collection knows that this most diverse and species-rich plant family can display truly bizarre yet strangely beautiful forms. Literally every day, some improbable flower comes into bloom in our greenhouses. But there is one plant that invariably causes jaws to drop when viewed in full bloom. Most onlookers agree it is among our most spectacular and prized orchid species in the collection.
Habenaria medusae is a terrestrial orchid from monsoonal habitats in Indonesia and mainland southeast Asia. Producing a basal rosette of leaves from a subterranean corm, the plant is fairly nondescript until it sends up a 20-inch inflorescence bearing ten to twenty or more truly astounding flowers. Most prominent is the outstanding lip, composed of finely dissected, radially arranged fringe reminiscent of Medusa’s head of snakes, from which it gets its name. One might ask why such a lip evolved in the first place; in this case it is still somewhat of a mystery. Thought to be moth-pollinated because of its white color, sweet evening fragrance and nectar spur, the deep fringe is actually a fairly commonplace feature of moth flowers. Though no one knows exactly why, something about these deeply fringed flowers acts as a highly effective attractant to moths.
Habenarias are known for being difficult to cultivate, intolerant of poor or chemically treated water, and needing a strict, dry winter dormant period. They rot easily if watered during their dry season. Despite its sensitive nature, the Smithsonian’s specimen has proven to be more amenable than most to cultivation and has bloomed three times since being purchased as a small bulb from a vendor from Singapore at the World Orchid Conference. This year the plant was selfed (pollinated with its own pollen) to create more seedlings of this delightful species and also crossed with a related species with a deep coral pink lobed lip in the hopes of producing flowers with a colorful medusa lip.
-Tom Mirenda, Smithsonian Gardens orchid specialist
Visit our orchids at the United States Botanic Garden’s exhibit Orchid Symphony, a collaboration between Smithsonian Gardens and USBG, now through April 27th, 2014!
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