The task for whoever designs a garden: “We predict the future – we see what does not exist.”
So expresses Ethan Kauffman, the director (and chief astrologer) of Stoneleigh, a public garden that opened five years ago on a historic estate in Villanova, Pennsylvania.
The thing is, gardeners need to see what too is there. In the case of the 42 acres Stoneleighwhich included seven acres of pachysandra when Mr. Kauffman first saw the property nearly seven years ago.
In any context, a sea of what was once a go-to ground cover—which has proven to be one of the ubiquitous legacy invasives of ornamental horticulture—would be overwhelming. But Mr. Kauffman, the former director of Moore Farms Botanical Garden, in South Carolina, has been hired to accomplish a mission that makes it even more difficult.
He is guided by what he calls the “conservation ethos” of Stoneleigh’s parent organization, Natural Landsa nonprofit group that currently cares for more than 23,000 acres in eastern Pennsylvania and southern New Jersey – at 42 nature preserves and at Stoneleigh – and has conserved more than 135,000 acres over its history, dating back to the 1950s.
To complicate matters further: Every garden feature he conceives must somehow complement the backdrop of a Philadelphia Main Line estate, with its 17,000-square-foot Tudor Revival stone mansion and massive, century-old stone pergola.
Can an ecologically focused landscape of native plants be integrated into such a place? The answer from Natural Lands and the Stoneleigh horticulture team is emphatic: Yes.
First Things First
When Mr. Kauffman arrived, the property had not been gardened in more than four years, beyond basics like mowing. Where to start?
His crew—which has just five full-time members and one seasonal horticulturist—went on some of the pachysandra-infested acres. (The current score: two down, five to go.) They knew it would be easy to fall into that tree-for-tree trap, however, distracting the obvious when the less-than is more urgent. So they emphasized higher value tasks. Their priority list would make a good road map for starting or renovating a garden of any scale or purpose.
First, they identified a number of key areas to focus on in the initial phase, to establish their larger intent – an early statement that previews longer-term goals.
Also critical, in self-defense: Any bare ground is an invitation to weeds, and will require many hours of maintenance if left vacant. So they planted empty places as soon as possible.
Third, where trees and shrubs were part of the eventual plan, they knew they had to get them into the ground. This was especially urgent with the natives that Mr. Kauffman specified for the renovated landscape, many of them new or unusual in the children’s business and only available in small sizes. The time spent waiting for the reward would be extra long.
Identifying key areas for maximum impact was easy: The parking lot would make the first impression on all visitors — currently about 40,000 a year, admitted free Tuesday through Sunday, except for Thanksgiving and Christmas.
But there lived about an acre of buckthorn. Ten dump truck loads were banished in favor of combinations like pink dogwoods ( Cornus florida Cherokee Brave ) underplanted with golden ragwort ( Packera aurea ). The yellow flowers of the ragwort coincide with the spring flowering of the trees, creating a more polite welcome mat.
The main house, formerly home to the Haas family, was another key destination. It needed some botanical brightening, as did the majestic, 220-foot-long pergola. A lawn grew under the pergola, not the beds of perennials that Mr. Kauffman envisioned. It begged for vines to climb up and over it too.
“The pergola is really charismatic,” he said. “We thought this was something that if we could do one small section – and hopefully do a good job with it – it would give visitors an idea of what’s to come.”
Also, he added, it was “an opportunity to showcase a lot of native vines that people might not use.”
Today, 24 types of native vines climb the pergola, including the lesser-grown yellow passion flower ( Passiflora lutea ) and a domestic subspecies of hops ( Humulus lupulus ssp. americanus ), its female flowers clustered in small green, pinecone-like structures. . Small-flowered Clematis shares the real estate, along with a Victorian favorite beloved for its giant leaves and the curious, hidden flowers that inspired its common name, Dutch pipe ( Aristolochia macrophylla ).
On another upright pergola, a prairie rose (Rosa setigera) has already reached 20 feet. It is also trained to transform lamp posts on the grounds into flowering columns.
Selected varieties of the better known trumpet honeysuckle ( Lonicera sempervirens ) and trumpet creeper ( Campsis radicans ) make a big splash too, along with American wisteria ( Wisteria frutescens ) – not the invasive Chinese species.
A design trick with the honeysuckle and trumpet creepers: “We plant them in clusters of three,” Mr. Kauffman said, “with a red, yellow and orange variety all in the same hole, to create these colorful explosions.”
Some home gardens don’t have such a vertical structure, but that doesn’t have to mean no vines.
“People say, ‘I love wisteria, but I can’t put it in my yard,'” Mr. Kauffman said. “And I’m like, ‘Well, yeah, you can. You can treat it like a bush.’”
Once in the ground, the young one-gallon plants are staked and then pruned immediately after flowering, and again later each year, as needed.
The forest (Decumaria barbara) is treated similarly – and could double as a ground cover.
“I just look at plants and I think, ‘What are the possibilities?’ Mr. Kauffman said. “And we experiment with them. That’s what we do as gardeners, right? We’re just having fun.”
Trees With A Difference, Hedges With A Purpose
Mr. Kauffman explores versatility – and not just with vines. The pergola plantings include trees such as weeping yellowwood ( Cladrastis kentukea White Rain) which are pruned to train it.
The skeletons of two venerable dead trees — an English yew ( Taxus baccata ) and a London plane tree ( Platanus x acerifolia ) — were not erased, but turned into outstanding sculptures. Others left standing as thickets, or natural trees, host families of birds and mammals, and support more native vines.
On the stone walls of the mansion, oriental redbud (Cercis canadensis) and box elder (Acer negundo) are espaliered, anchored with eye hooks screwed into the mortar, as are more vines, and shrubs.
Witch hazel (Hamamelis virginiana), specifically striking Lemon Lime, inhabits one wall. “It’s this crazy, variegated green-and-yellow selection that looks like something out of ‘The Matrix,’ but it’s pretty eye-catching,” Mr. Kauffman said.
On the large, covered stone gates, or lychgates, the white-flowered weeping oriental redbud Vanilla Twist is trained, vine-like, around the posts. “We cut off all the side branches,” he said, “and just let it do its thing.”
When he got to Stoneleigh, there really weren’t any hedges. “Most of the experience was just this open-ended kind of journey,” he said. “You really didn’t have anything dividing it or creating visual barriers, and we knew that was going to be important later.”
One beautiful example is a row of dwarf Teddy Bear Southern magnolias (Magnolia grandiflora). A white pine (Pinus strobus) teams up with an American rowan (Thuja occidentalis Smaragd) in another hedge, with a lone, golden-leaved Yellow Ribbon tree in the row, screaming for attention.
Shrubs-in-hedges include scrub (Baccharis halimifolia), hearts-a-bustin’ (Euonymus americanus) and obscure native, tall marsh privet (Forestiera ligustrina), “a great replacement for our non-native privet,” Mr. Kauffman said. , referring to another serious invasive.
“And we have this crazy natural hedge that has 70 different varieties of native woody plants, in a double row,” he said. “It’s 200 feet long, about eight feet high. We have grapes there, and perennials — it’s kind of a dynamic thing.”
Covering Some Ground
The hedges are just one “indication for care,” Mr. Kauffman said, a sign that this is a garden — albeit less conventional than its predecessor.
The team’s approach to what was once 14 acres of mowed lawn is another hint.
“We let at least half of it go in no-mowing, and it looks so beautiful,” Mr. Kauffman said. “We mow the edges — the first six feet — so you can tell we’re taking care of it, but the rest we just let grow long.”
Fewer weeds are another sign of human intervention. Living “green mulch”, in the form of ground cover, is the main tool in Stoneleigh’s campaign against them.
Golden ragwort provides good coverage against unwanted species, as does desert strawberry (Geum fragarioides, formerly Waldsteinia). Sedges (Carex), Canadian ginger (Asarum canadense) and creeping phlox (Phlox stolonifera) are other powerful partners in this naked effort against weeds.
“As a small staff, you just have to find a way,” Mr. Kauffman said. “And we are experimenting: With bare, grassy areas that we are sick of, we will plant only Parthenocissus. And after a year we don’t have to deal with it.”
This may surprise gardeners who too often pull up Virginia creeper (Parthenocissus quinquefolia) or dense creeper (P. inserta), native vines that are often misunderstood, despite their high natural value and brilliant fall color.
Could we change our thinking and start factoring them into our garden plans? That depends on our way of seeing – on how we visualize the way forward.
Margaret Roach is the creator of the website and podcast Path to Gardenand a book of the same name.
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