Posts tagged ‘garden maintenance’
June is National Rose Month

Glass lantern slide of an unidentified garden, c. 1920. Archives of American Gardens, J. Horace McFarland Collection.
We’re bringing our month of wedding-themed #ThrowbackThursdays to a close with tips for caring for roses at home from Smithsonian Gardens horticulturist Shelley Gaskins. Shelley manages the Kathrine Dulin Folger Rose Garden next to the Smithsonian Castle.
June is one of the most popular months for weddings, and it’s also National Rose Month! Roses are a traditional and elegant flower choice for wedding bouquets and decorations. Did you know that Tricia Nixon was married in the White House Rose Garden in June of 1971? The White House Historical Association has a new exhibit exploring the Rose Garden during the Kennedy administration opening on July 16th. “The Kennedy Rose Garden: Traditionally American” features a few photographs and letters from the Archives of American Gardens. Did you choose roses for your wedding? Share your story in the comments!

‘Amber Queen.’ This rose, and all of the roses pictured below, can be found growing in the Kathrine Dulin Folger Rose Garden next to the Smithsonian Castle in Washington, D.C.
Rose Tip #1: Do your research! Roses are rated on several characteristics. Choosing roses that are rated as resistant to fungal diseases such as black spot and powdery mildew should top your list.
Rose Tip #2: Roses require at least 6 hours of full sun (preferably in the morning), a well-drained and nutrient-rich soil, and moderate amounts of water. Water should only be applied directly to the root zone, not to the leaf surface. Adequate sunlight and water will help decrease the spread and incidence of fungal diseases.
Rose Tip #3: When pruning roses in early spring, prune with the understanding that opening up the center of the plant allows for light penetration and air circulation. Allowing light and air into the center of the plant will create an environment that is less favorable to fungal diseases. Be sure to clean the edge of your pruners with alcohol to avoid spreading viruses.
Rose Tip #4: Eliminating dead, dying and diseased plants and plant parts from your garden will help to keep your garden healthy. This includes cleaning up potentially diseased rose leaves that have fallen from the plant. Fungal spores can overwinter and return to the plant from the fallen leaves.
Rose Tip #5: Not all bugs are bad! get to know the insects that visit your garden. Find out which insects truly pose a threat to the health of your plants (pests). Find out if the pest has any natural predators (beneficial insects). A healthy garden should have both. If necessary, you can introduce mail-order beneficial insects into your garden.
Rose Tip #6: Beneficial insects are often beneficial only at certain stages in their life cycle. For example, the syrphid fly only feeds on prey while they’re in their larval stage. Adult syrphids don’t eat other insects, they eat nectar and pollen. You should plant flowers that provide a variety of nectar and pollen sources throughout the growing season.
Rose Tip #7: Last one! Plant families that will help attract beneficial insects to your rose garden, including:
- Apiaceae (or Umbelliferae) -Carrot Family- attracts lady bugs, parasitic wasps, and predatory flies.
- Lamiaceae or Labiatae -Mint family
- Asteraceae -Daisy Family- attracts hoverflies, lacewing, lady bug beetles, minute pirate bugs, and spiders.
The Smithsonian Gardens Tree Collection: Proactive Management

This American elm tree on the grounds of the National Museum of Natural History is over two hundred years old. Eric Long, photographer.
The Smithsonian Gardens Tree Collection currently consists of over 1,850 trees, approximately 1,400 of which are located on the downtown Washington, D.C. and Anacostia campuses. These trees add beauty to our grounds, and they offer myriad environmental and health-related benefits. Unfortunately, it seems that trees are constantly under attack by a host of problems, ranging from severe climate, to native and exotic pests and diseases, to damage from construction and development projects, to the tough urban environment in which they grow. Once these plants become stressed, it’s more likely that they will suffer due to one or more of these issues. In addition, as trees grow, certain structural defects can develop which may cause problems in the future, especially when severe weather events can exploit the inherent weaknesses in these defects.
For these reasons, we at Smithsonian Gardens take a proactive, rather than reactive, approach to caring for these green assets. Oftentimes, defects, cultural stressors, or insect and disease infestations that have gone unnoticed for a time can be difficult, if not impossible, to reverse. Therefore, a thorough health and structure assessment of these trees was completed at the end of 2014. This assessment consisted of a top-to-bottom, 360 degree visual evaluation of each tree. All defects and other potential issues were noted and assigned a rating based on the severity of the condition observed.
What we had at the end of the evaluations was a complete list of trees, their problems (if they had any), and recommendations for correcting anything of concern. Based on the ranking system, we now have an organized and detailed list of what maintenance and tree care work is needed, with a clear indication of where we need to start. This has enabled Smithsonian Gardens to find and fix issues before they become more serious, and gives us the ability to be proactive with our tree management. It also gives us a better idea of how to budget for upcoming maintenance needs. Prevention is the best medicine, and any time we can find and correct an issue before it becomes serious it allows us to keep our trees happy and healthy for many years to come.
-Greg Huse, Smithsonian Gardens Arborist and Tree Collection Manager