A Walk Around the Borough
In the Garden with Andrew
Viburnum plicatum, the Japanese Snowball, is now listed as an invasive exotic. Photo: Andrew Bunting
When I talk to friends, family members, and colleagues, we often try to find silver linings to the COVID-19 pandemic. For me, one is my now ritual weekly walk through the borough, up to Swarthmore College and Scott Arboretum, then back home. I have lived in Swarthmore off and on for 34 years, and I continue to be amazed by the incredible diversity of gardens and plants grown by local residents. Every week, I see a plant in someone’s yard that I did not notice before, or enjoy a tree or shrub that I have watched mature over the years.
A house on Elm Avenue has one of the nicest specimens of the paperbark maple, Acer griseum, I have ever seen. And on the corner of Elm Avenue and Chester Road, a massive Burkwood viburnum, Viburnum x burkwoodii, is blooming in front of a multi-dwelling college house.
The neighborhood near the post office features many of what I consider old-fashioned shrubs, their heyday likely the 1920s and 1930s. Yesterday, at two different houses, I saw massive specimens of the double-file viburnum, Viburnum plicatum subsp. tomentosum, its flat-topped clusters of white flowers in full bloom. A close relative, Viburnum plicatum — the Japanese snowball — has “balls” of white flowers. Unfortunately, both shrubs have been so successful as cultivated plants that they now appear on lists of regional invasive exotics along with the Norway maple, Acer platanoides, and the burning bush, Euonymus alatus.
The borough also boasts many kinds of great old-fashioned spireas. On Harvard Avenue, I spotted a venerable specimen of the bridal-wreath spirea, Spiraea x vanhouttei. This tall, upright shrub is festooned with clusters of white flowers on somewhat pendant branches, making it look as though the flowers are cascading down the branches.
Dogwood Lane had many houses with the flowering dogwood, Cornus florida.
One of the highlights of last week’s walk was an enormous Gelsemium sempervirens, its tubular yellow flowers covering probably 20 feet of the house. Commonly known as Carolina jessamine, or false jasmine, the plant is native to the southeastern U. S. If you drive south on I-95 in the spring, you will see the yellow flowering vine on the fencerows of southern Virginia. In the South, it tends to be evergreen; in our climate, it is semi-evergreen. A twining vine, it needs a trellis or some other support on which to grow. A cultivar called ‘Margarita’ — selected for its abundance of bright yellow flowers — is fairly cold hardy.
On Dickinson Avenue, I observed an entire bank covered in a fairly uncommon perennial, Erigeron pulchellus, a creeping daisy-like plant whose common name is Robin’s plantain, or fleabane. A real find!
Reader Questions
Basil and Daffodils
Marcia Hiehle of Swarthmore wrote to ask: “The quarantine has inspired an urge to plant basil. What tips do you have? Can I keep critters from eating it? Where to plant? What variety?”
Rutgers Obsession, Devotion, Thunderstruck, and Passion basil. Photo courtesy of Rutgers University.
Do not plant too early. Basil does not like cold weather. Wait until at least mid-May, but June 1 might be best.
Grow plants in terracotta pots for better drainage. Basil dislikes the heavy, moisture-retentive soils that we have in this area. Pots should also provide protection from animals.
When basil flowers, pinch or prune out the blooms to encourage more leaf growth.
Plant a few crops throughout the summer, so you always have good basil.
Good selections: ‘Devotion’, ‘Obsession’, ‘Passion’, and ‘Thunderstruck’ were bred at Rutgers University for powdery mildew resistance.
Grow in full sun and don’t overwater.
I am often asked what to do with daffodil foliage.
The simplest answer is: nothing! You will often see gardeners clumping it together and wrapping it with a rubber band. This is not necessary. You can simply let the foliage turn yellow, and then remove it once it is completely yellow. Don’t rush it, because the foliage must photosynthesize as much as possible so the bulbs can store enough carbohydrates.
Send your gardening questions to editor@swarthmorean.com.
Happy gardening!
Andrew Bunting
Andrew Bunting is vice president of public horticulture at the Pennsylvania Horticultural Society and vice president of the Swarthmore Horticultural Society.
