August’s Bloom Where You Are Planted Edition
Photo by Paul W. Meyer
Our History at Home offerings typically sprout from history and architecture. Today, and once every month, we offer a conservation cornucopia from the Conservancy and some friends on trees, gardening, and stormwater management. We hope to help you “Bloom Where You Are Planted.”
August – Green ash
by Paul W. Meyer, Conservancy Board Member and
Morris Arboretum’s Retired F. Otto Haas Executive Director
Green Ash – Fraxinus pennsylvanica
Green Ash is a native tree, widely distributed across eastern North America. In its natural setting, it occurs most frequently along streams and in low, moist areas. The wood of ash trees is notably strong and relatively light. It is the preferred wood for baseball bats, and it is also often used for tool handles. Until recently, it was widely planted in some cities as a street tree.
That strategy changed dramatically with the arrival of the emerald ash borer, a destructive insect which arrived from Asia. First documented in Southeastern Michigan in 2002, it is believed that the borers came hidden in the wood of shipping crates from China.
The beautiful emerald-green female adults lay their eggs in bark crevices of the ash trees. When the eggs hatch, the larvae bore into the tree and feed on the inner bark and phloem, girdling the tree, thereby causing extensive canopy dieback and eventual death. When the emerald ash borer moves into an area, it is nearly 100% fatal to both green ash and its close relative the white ash (Fraxinus americana). Today, dead and dying ash trees are a common site in Chestnut Hill. Once infested, the tree should be quickly removed before it becomes brittle and dangerous.
Trees that are still healthy can be protected with systemic insecticides. These insecticides can be applied as soil drenches, trunk injections or as sprays on the bark of the lower trunk. They cannot reverse damage that is already done, so it is important to begin treatment early, ideally before symptoms of crown thinning and branch dieback begin. Detailed information on the emerald ash borer and its treatments can be found here:
For now, of course, ash should not be planted. Looking to the future, US Department of Agriculture is conducting research on several species of stingless wasps that attack the emerald ash borer larvae and eggs. They have been released in 25 states and early results are encouraging.
Also, some Asian species of ash have shown natural resistance to the emerald ash borer. Many of these have been collected by the Morris Arboretum in collaboration with other arboreta in the US, Canada and China, and are growing successfully in their collections. These may be used in breeding or gene editing to produce resistant hybrids. These are potentially long-term solutions, but meanwhile many more millions of ash trees will die.
The demise of the ash is another cautionary example of the importance of maintaining high levels of diversity in our urban tree plantings. As with the American elm, American chestnut, and the Canada hemlock, virulent insects and diseases have devastated our populations of these susceptible species. By maintaining maximum species diversity, we can hedge our bets and help ameliorate the impact of these and future epidemics in our community’s urban forest.
See the full gallery of images HERE.
Photos by Paul W. Meyer
Top: Green ash growing on the banks of the Schuylkill River, in its typical riparian habitat.
Second: Green ash, at its best, formerly growing at the Morris Arboretum Bloomfield Farm.
Third: Declining ash on Evergreen Avenue near Stenton Avenue.
Fourth: Germantown Avenue planting of green ash showing symptoms of emerald ash borer infestation.
Fifth: Highland Avenue ash tree showing canopy dieback and typical epicormic branches arising from the main trunk (another symptom of borer damage).
Sixth: Green ash bark detail.
Bottom Photo: Illustration of green ash by Pierre-Joseph Redoute’ from The North American Sylva (1817).
See the entire gallery of images for this month’s article at our Tree of the Month page! Visit our History at Home page for more information.
Chestnut Hill Conservancy is regularly highlighting special trees in our community, both large and small, as well as common and obscure. In doing so, we hope to promote an appreciation of our arbor legacy and foster a culture of stewardship and renewal of this invaluable resource.
August – Container Gardening
by Emilie Lapham, Conservancy Board Member, avid gardener, botanical artist, and active participant in several noted local and national garden organizations.
Container Gardening
Another dimension to gardening
Gardening in containers can add dimension and interest to any place or property. Actually, no land is required for this kind of garden, making it possible for almost any location, including public spaces. Planted containers can be up in the air, on the building or freestanding on the ground and can be seasonal or year round. Many of the examples shown here are located in Chestnut Hill on Germantown Avenue and are planted by the Garden District Fund and in Wyndmoor on Willow Grove Avenue as part of the restaurant, Enza.
Public spaces are greatly enhanced by container plantings adding living decoration for all to enjoy. Containers can be planted for decoration and for practical reasons such as privacy or herbs for the kitchen.
Look first at the architectural context the planting will be in, to choose containers that are complementary. Color, scale, texture and shape are good things to think about when selecting containers. Another important detail to remember is weather conditions; freezing temperatures will crack some containers if they will remain outside year round. Repurposed vessels can be interesting choices, so be creative. It is possible to make hypertufa troughs or wood boxes, but start simple.
Think about moisture retention, although containers can also be lined to improve moisture levels. Containers should have drainage.
Color scheme might be the first thought, then size and texture combinations. Monochromatic plantings can be a very sophisticated and elegant choice. Boxwood in an urn is very classic and easy. Sometimes keeping to just one potted plant is plenty and grouping planters with various plants makes a pleasing visual display.
For a large pot, a big upright with bold leaves contrasts well with a variety of colors and textures midway and then cascading plants down the side of the pot.
Consider it a small landscape with graduating heights and contrasts. Select plants that have similar light and water requirements per planting.
For most containers a potting mix will provide a good environment and some mixes help retain moisture and also contain slow release fertilizer. You may need to add fertilizer later in the season. Very large containers might need filler to reduce soil needed and reduce the weight. Broken pots or gravel can be used for filler. A top dressing can be attractive and help with moisture retention also. Snip leggy growth and deadhead spent flowers as the season progresses and of course water as needed. Be careful to water more frequently during hot spells.
Here is a chance to experiment and try new gardening ideas each year.
All Photos by Emilie Lapham
Top: Containers create a garden at Enza, Wyndmoor. Second: Bold colors light Germantown Avenue. Third: Chestnut Hill, blooming! Fourth: Just one plant. Fifth: The Container disappeared. Sixth: Robertson’s harmonious colors. Seventh: A well-dressed window. Eighth: Blend colors and textures. Ninth: Variety of containers, grouped. Tenth: Hypertufa trough with Dwarf Lilyturf, Ophiopogon. Bottom: Strawberry.
See the entire gallery of images for this month’s article at our A Gardener’s World page! Visit our History at Home page for more information.
We’re thrilled to present to our members a special extended virtual tour of Louis Kahn’s Margaret Esherick House. If you missed the tour of this mid-century architectural treasure during this year’s Architectural Hall of Fame virtual Celebration, or even if you were able to attend, make sure to tune in!
On Wednesday, September 1st at 5 pm, we’ll broadcast a one-hour, members-only program, including an in-depth version of Bill Whitaker’s fascinating look at the details and significance of the Esherick House, featuring 20 extra minutes not previously aired during the May 22nd event. At the conclusion of the tour, we’ll also have a live Q&A featuring current Esherick House owners Dan Macey and Paul Savidge!
We’re excited to share this tour as a thank you to all of our membersClick here to register!
You must be a member to attend. Click here or email to join or renew.