The mid-point of the summer season is here, along with the August people, but the gardens have hurried along until one must ask, what is left? Rose of Sharon, phlox, Oriental lilies, Rudbeckia ‘Goldsturm’ — the backbones of the late summer garden — have been in bloom with us for weeks already and seem ready to become passé soon. Annuals are looking tired too, due to insects, heat, and humidity.
Good culture rewards those who employ its techniques and “separates the sheep from the goats.” Gardeners know this but cannot always determine what is the best course to take. There is always more that can be done to yield results, although sometimes the prospect is daunting. Gardens become exhausted and leached over time, as do their owners. Lifting all the perennials in the border? Digging in compost? Splitting the clumps? Turning the compost heaps? Get me to my hammock!
I recommend two gardening books with many strategies for maintaining the attractiveness of the garden. Tracy DiSabato-Aust’s “The Well-Tended Perennial Garden,” (expanded edition, Timber Press, Portland, 384 pp. $34.95) has become a hands-on classic for American gardeners, with techniques and management of dozens and dozens of perennials thoroughly discussed. It contains 276 color photos.
“A Book of Gardening: Ideas, Methods, Designs,” by Penelope Hobhouse for The National Trust (UK), (Henry Holt & Co., New York, 1995, 318 pp.) is a guide to the ideas and techniques behind the creation and maintenance of Britain’s National Trust gardens. Famous ones, such as Sissinghurst, Tintinhull, Hidcote, Powis Castle, and many more, are deconstructed and described within the pages.
The British are far more detail-oriented, practicing what might be called “high horticulture” in their gardening, than we typically are over here. This is, nonetheless, a how-to book every bit as much as “The Well-Tended Perennial Garden.” It contains many valuable charts, tips and ideas, as well as enticing color photos of National Trust gardens.
Countering horticultural hype
Patrick Cullina, best known for his connection to New York’s High Line and Brooklyn’s Botanic Garden, gave a worthwhile talk with great photographs at Polly Hill Arboretum on August 1, “Shopping for Paradise: Gathering Perspective in the Pursuit of Plants.” He poses the question, how does one distinguish real value from novelty in the catalogue and at the garden center?
The hype involved in marketing horticultural products must sometimes be obvious to their purchasers. An example is the astonishing array of named Heuchera varieties, many of which sport names of alcoholic beverages and mouth-watering desserts, ‘Crème de Cassis,’ ‘Peach Melba,’ and ‘Key Lime Pie.’ As consumers, are we really that adolescent (or senile)?
Cullina offered suggestions for when plants do not succeed as expected. Concerning the bewildering array of hybrid Heucheras with those appetizing names, he suggests shopping for those that carry the genes of the North American species, H. villosa and H. americana: for example ‘Dale’s Strain,’ a selection of H. americana; and H. ‘Tiramisu,’ hybridized with H. villosa genes.
Needing to replace an ailing honeysuckle, I appreciated his timely endorsements. Among the many plant groups he discussed, Cullina promoted plants we possess as part of our native palette, which may be better-adapted and more satisfactory over time, especially in “the new normal.” Shrubs such as linderas, sumacs, aronias; vines such as the native honeysuckle, Lonicera sempervirens; panicums, muhlenbergias, and sporobolus among the grasses, and many more, are as good or better than it gets with the patented plants in the pink or blue pot systems.
Fortunately there are organizations that exist to help gardeners struggle through the thickets and vegetation. The National Garden Bureau (ngb.org/index.cfm) and its sister organization, the All-America Selections (all-americaselections.org), and the Perennial Plant Association (perennialplant.org) are three such. Right here on the island, Polly Hill Arboretum (pollyhillarboretum.org) is another one. When these groups promote plants or varieties, it is vetted information, as is advice from nurseries that grow the products they sell.
Clematis x durandii
Clematis have a reputation as tricky or difficult plants. Possibly this is due to diseases, such as wilt, that may plague them, or confusion about pruning that results in flower loss. This is a shame, because few plants are capable of delivering so much drama to the garden, and pleasure to the gardener, as clematis do.
A favorite of mine that has proved reliable over the years is Clematis x durandii, Integrifolia group, also known as solitary clematis. Since I do not often encounter it in gardens I visit, I’d like to train the spotlight on it.
From clematis.com: “One of the oldest Clematis hybrids. Raised by Durand Frères, France, 1870, by crossbreeding C. integrifolia and C. lanuginosa. Deep blue, bell shaped flowers become flat when fully open, borne from June to September.”
The plants are winter hardy and undemanding here, preferring, however, fertile soil. They are non-twining vines, that is, the stems are lax and do not hold fast to supports. Left on its own, C. x durandii sprawls through a planting charmingly, yielding touches of cobalt blue where the large, five-inch blossoms open. The flower centers hold a prominent bunch of yellow anthers. C. x durandii may be tied-in to supports at the back of the border where it forms a backdrop four or more feet tall, again contributing those splashes of inscrutable deep blue.
Clematis x durandii is pruned hard in the spring, back to the first set of buds. I grow it through and upon a pressure-treated lattice fence where it mingles with Rosa ‘Nymphenburg.’ The foliage is as clean and elegant as the flowers, large as my palm, elliptical, in pairs at the nodes, mid-green. Snap up this plant if you see it! Find or create a setting for it in your garden. You will admire it endlessly.