Posts filed under ‘Horticulture’
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
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!