At a recent meeting of authors and booksellers in Cambridge, Massachusetts, as we were all saying our goodbyes, a magazine editor handed me her card and asked if I would be interested in writing for the gardening section of the monthly publication. We maintained our rapid advance to the exit as I responded without hesitation, “Absolutely!” She then suggested a topic that she felt would interest readers: what would I suggest planting in a small garden area to provide ornamental interest throughout the year?
We reached the exit and the discussion abruptly ended before I could begin to consider the question. I needed more information. Is the hypothetical garden sunny or shady? What are the soil and drainage characteristics? I had just enough time to suggest that the article-to-be should focus primarily on native plants as my possible editor-to-be scurried away.
It is an intriguing question and I have spent considerable time since this encounter thinking about it. I’ve decided to rush headlong into an answer in this week’s essay, presenting two small trees and one shrub that are native to New England along with one non-native plant that can be grown as either a large shrub or small tree. Next week I’ll deal with groundcovers and herbaceous perennials.
Throughout New England, the pagoda dogwood (Cornus alternifolia) can be found growing beneath the forest canopy. With a mature height of 25 feet, it is the perfect tree for the shady corner of a small garden where, in late May to early June, it displays large flat clusters of creamy white flowers on tiers of horizontal branches. In late summer, birds feast on its purple black berries. And in October, its leaves are colored with a mix of yellow, red, and purple.
One note of caution for gardeners growing this tree: a fungus disease called “golden canker”, named for the yellow discoloration of infected stems, attacks trees under stress. Growing pagoda dogwood in the garden should include siting the tree in the shade of taller trees and avoidance of drought stress. On a much more positive note, pagoda dogwood is mush less susceptible to the anthracnose fungus that in recent years has curtailed the use of flowering dogwood (C. florida) in New England landscapes.
The redvein enkianthus in Marjorie’s Garden (Enkianthus campanulatus, native to Japan, hardy throughout New England to Zone 5), now in its tenth year, flowers in early June, clusters of creamy-yellow bells with deep red veins hanging below the whorl of leaves at each branch tip. Enkianthus flowers are slightly larger than those of highbush blueberry but have the same drooping habit and the same ability to attract bumblebees.
In autumn the leaves of our enkianthus first turn a bright golden yellow with some leaves still showing a little green. At this stage of fall color, the dark brown seed capsules provide a striking contrast in both color and texture. A few days later, the golden enkianthus leaves are infused with red. A few more days and the ground around the little tree is littered with these colorful leaves. Fall color is variable within the species with some plants turning all red or all yellow.
The clusters of rich brown deed capsules persist through winter. Capped with new snow, they make a beautiful winter garden scene.
The enkianthus in Marjorie’s Garden is now about 8 feet tall. We have pruned this naturally shrubby plant into a small multi-trunk tree, highlighting its layered branches. It may eventually grow to 12 feet in height, the perfect small garden tree in sun or partial shade. Kept in shrubby form, redvein enkianthus also makes a beautiful informal hedge.
Like other ericaceous plants, including blueberries and rhododendrons, enkianthus prefers an acid, moist, cool soil. Avoid planting it in hot, dry locations where spider mites will become a persistent problem.
Summersweet clethra, Clethra alnifolia, is a native plant success story, a favorite shrub among the many gardeners who grow it for its spicy fragrant summer flowers and golden yellow fall foliage. Also called sweet pepperbush for its peppercorn-like fruit, white alder for the similarity of its foliage to that of the true alders, and “poor man’s soap” because the flowers produce lather when crushed in water, summersweet has been in cultivation for over 200 years. It is an essential plant in the pollinator garden, attracting butterflies, bees, and hummingbirds, and it is ignored by deer, a draw for many New England gardeners.
Borne in dense narrow spikes, the blossoms fill the summer air of the garden with a spicy scent for several weeks in late July and August. While the species has white blossoms, many new cultivars of summersweet have been introduced in recent years, including ‘Hokie Pink,’ a compact form that grows in Marjorie’s Garden. While the species can reach heights up to 10 feet in the garden, ‘Hokie Pink’ tops out at 3 to 4 feet.
Individual flowers of summersweet open slowly, starting at the base of each spike. The result is a flowering period that lasts several weeks.
Following the bloom are small rounded seed capsules, each one-eighth inch in diameter and containing several seeds, all packed into the same dense spikes of their forebears. These tan-colored capsules persist into autumn, gradually darkening in color and adding textural depth to fall foliage that varies from light yellow to gold.
In winter I love to watch the snow build up around the summersweet in Marjorie’s garden until only the uppermost dried seed heads remain exposed. I imagine a field mouse beneath the snow, snuggled close to the ground with a cache of tiny seeds, waiting for the thaw.
‘Donald Wyman’ Crabapple
Crabapples are seldom touted as multi-season garden plants. All are beautiful in their spring flower display, but by the end of August the majority of varieties have lost most of their leaves to diseases and insects, leaving little opportunity for display of fall color. There are, however, a few notable exceptions including my favorite cultivar, ‘Donald Wyman’. At its October peak, this cultivar combines leaves of late summer green and bright yellow with the glossy bright red of maturing small apples, each about one-half inch in diameter, to create a striking autumn display.
The fruits of ‘Donald Wyman’ persist into winter, often still on the tree in late January capped with snow or wrapped in ice. When a midwinter thaw softens the apples, resident robins, waxwings (both cedar and Bohemian), and pine grosbeaks feast on the fruits, dropping bits of peel to create a reddish-brown shadow of the tree on the snow.
My first encounter with ‘Donald Wyman’ was my inaugural year as Director of the Lyle E. Littlefield Garden at University of Maine, Orono. I watched it through several years and it was always the best of the collection, small enough (20 to 25 feet tall and wide) to fit the corner of a small garden and truly a multi-season garden plant.
Crabapples need sun and we had run out of open spaces in Marjorie’s Garden until last summer when we decided to cut down some of the tall black spruce on the garden’s border. We now have a spot for this exceptional small tree.
I can visualize all four of these plants in a small garden with one corner shaded by the spreading branches of a red maple, the perfect spot for a pagoda dogwood. Across the way, a ‘Donald Wyman’ crabapple fills a sunny corner with white spring flowers, beautiful fall foliage, and bright red winter fruits. A grassy path winds around a central island bed where a tree-form enkianthus takes center stage in all seasons and, nearby, a colony of summersweet fills the August air with sweet perfume.