Martha's Vineyard Garden Club Report : Rock gardens
Tom Clark, the Collections and Grounds Manager at the Polly Hill Arboretum, presented his perspective on rock gardens at the May meeting of the Martha's Vineyard Garden Club. Mr. Clark admitted to being passionate about rock gardening ever since boyhood when he sprinkled baby rocks into the fertile soil of his western Massachusetts home in Hadley, and hoped they would grow.
Mr. Clark's perspective on rock gardening is first and foremost a reflection of his philosophy of gardening. "Gardening is doing it for ourselves," he asserted, adding, "Any type of garden is what you make it."
Using a slide projector to illustrate how an early Japanese Temple Garden promoted contemplation and used very little plant material, Clark illustrated his talk with panoramic alpine vistas, and examples of those ideal marriages of aesthetically pleasing stone works and plantings from public and private gardens.
Early rock gardens in the 1800s tended to emphasize towering rock works at the expense of accommodating plant materials. The shift to studying the special characteristics of alpine plants is apparent in the Royal Botanical Garden at Edinburgh, Scotland, where the soil requirements for the plants surrounding striking rock formations is taken into account. The rock garden at Smith College in Northampton is the oldest continuously maintained garden of its kind in the United States.
On the Vineyard we've got a lot of rocks that form the wonderful old stonewalls that thread through woods and make for striking foundations of houses. According to Mr. Clark, the stones provide the private gardener with the quintessential opportunity to "make rock garden lemonade" from haphazard granite outcroppings.
What is a rock garden? Mr. Clark formulated this definition for his audience: A rock garden is "a landscape designed and built to simulate natural rock surroundings in order for one to cultivate a harmonious display of rock plants, alpines, and other plants of similar habit and character."
Certain plants look appropriate with rocks whether placed in containers, troughs or on abandoned foundations or stonewalls. Since the use of plants is tremendously varied, Clark reminded his audience, "Nature is a wonderful teacher and source of inspiration." Not all rock gardeners are challenged to grow a perfect specimen found in the high elevations of Himalayan ranges that doesn't want to grow at sea level.
He reminded us, "No two rock gardens are alike," and said rocks are less important than maintaining the balance between plants and the rocks.
A container, or slightly raised bed of sedum, dwarf conifers, and Veronica constitutes types of rock gardens, but practical considerations of site portend the best results. "Don't fight nature," said Mr. Clark. Choose a sunny and open area for plantings requiring 5-6 hours of direct sunlight a day. A sloping or flat area is suitable, although a sloping site is more evocative of an alpine setting. Keep in mind that a well-drained site is critical. Ask, who will be viewing the rock garden and from what vantage point?
"So what's so great about rocks?" asked Mr. Clark. They form the visual backbone of the garden as well as provide cool soil beneath them. Spring plants are at their best in rock gardens, and rocks of size and character can often be found on one's own property, construction sites, or at a location recommended by others. But be cautioned against dismantling an existing stone wall, which is illegal.
In a talk that embraced all aspects of rock gardening, Mr. Clark offered insights on everything from how to move rocks without personal injury to a suggested ratio of one part loam, one part organic matter, and two to three parts gritty, coarse sand and crushed rocks for amending the soil of an average rock garden. A colorful display of typical and suitable plantings rounded out the talk, and the speaker closed with a quotation from Laura Louise Foster, a botanical artist, who recognized "...the deep glow of satisfaction (that comes) to those who create their own landscapes, the child of their imagination, molded by their own labor, and nurtured by the care of their own hands."
The Martha's Vineyard Garden Club Report will appear the last week of every month.