Gardens By the Seashore
Thursday, August 2, 2007
LEWES, Del. -- The beach garden of Christopher and Doris Valenti is strikingly colorful: Out of a sea of pink petunias, large clay pots rise up and support plantings of angel's trumpets and coleus. Elsewhere, other containers are dripping with a blue, daisylike annual called brachyscome that is holding up well in the heat and humidity.
This is merely a prelude to the main show, an enclosed lawn whose flower beds are a heady mix of annuals and perennials. In the far corner, a waterfall gushes into a large, naturalistic pond filled with canary yellow lilies. The mood is of relaxed exuberance, which seems fitting for a garden in August at the beach.
And yet, as Christopher Valenti will tell you, putting together a landscape here is anything but relaxed or carefree. Think about the challenges -- a hotter climate than Washington's, winter storms, high water tables, salt spray and impossible soils -- and you may consider instead finding a high-rise condo. But as more baby boomers build or buy beach houses as second homes, they are forced to confront landscaping issues that are unexpected and frustrating.
You might think the predominant soil type near a beach would be sand or sandy silt, but the changing ocean levels over the ages actually laid down clay marshland over sand and vice versa, said Valenti, a onetime marine biologist. No two sites are quite the same, and there can be starkly different microclimates even within a single garden.
All this is more than an academic exercise for Valenti, who heads J.B. Landscaping here. The firm's 30 employees design, install and maintain gardens on the Delaware and Maryland shore.
As in creating a successful garden anywhere, the soils and climate should be known before planting near the ocean. And with the extremes of the seaside environment, that exercise becomes especially important. "Sometimes we can dig down six feet and we'll hit beach sand," Valenti said.
The Valentis' home mimics a Victorian clapboard house, and after 17 years the front display garden, covering 10,000 square feet, is well established. All but an existing sweetgum tree were added, a tree that stood in silent testament to the site's wetland conditions: a high water table with nowhere for rainwater to drain.
A series of drains has fixed the surface ponding, but when Valenti used a tree spade to install a southern magnolia, he got a glimpse at what lies below the Eden he has created. "Black, silty clay mud," he said. It reminds me of gardens I have seen in the Netherlands: intensively cultivated beds perched 18 inches above a subterranean sea.
The magnolia is doing well, as is the related sweetbay magnolia near the pond, a tree notoriously difficult in hot, dry sites. Its size and vigor suggest it has tapped in to the ground water. Elsewhere, Valenti has found another perfectly matched tree for the soil conditions, a specimen weeping Alaska cedar that has grown to 30 feet.
The more difficult conditions of sand without underlying moisture present different challenges, and if clients want colorful gardens in pure sand, he will add a layer of one to two feet of topsoil and add drip irrigation. "It's almost hydroponics."
There is the idea that a garden at the beach should have a certain look, but the dune grasses people think of are usually garden varieties of non-native ornamental grasses such as miscanthus and pennisetum. Valenti used to use these plants a lot more, but he says that they proved to be high-maintenance. They generate a lot of annual top growth to be removed in the winter, and after five years the clumps of miscanthus in particular become so thick that you need a backhoe to lift and divide them.
Not that true native plants are necessarily bulletproof; conditions vary so much from one area to another that a gardener may be putting a swamp plant in a site that reveals itself to be too dry. Valenti thinks of the seaside goldenrod, a showy, yellow-flowered perennial that grows close to salt water. Put it in rich garden soil, Valenti said, and it develops a rust disease. And to survive, dune grasses need the annual shifting of sand to cover their lower stems.
And consider the beach plum. In the windswept paucity of the dune, it may take a century to reach eight feet in height. Put it in the garden and it takes on the proportions of an apple tree.
Nor'easters take their toll, bringing salt spray as much as 40 miles inland. The salt damage to plants is usually mitigated, however, by the rainwater deluge that accompanies the storms. The bigger problem is the desiccating effects of fierce winter winds, Valenti said. His garden is three-quarters of a mile from the Delaware Bay, and when the winds are from the northeast, they travel 80 miles over open water with nothing to slow them, he said. In his garden, he has seen one gardenia flourish and its neighbor, exposed a little more to the winds, struggle.
As it rushes between close-set beach houses, the wind becomes even more intense. "Japanese black pines, which almost never get windburn, will be burnt by that venturi effect between two houses," Valenti said. "We will plant grasses that will conceal the damage."
His own garden is also used to test annuals and perennials for beach conditions. Cannas, hardy and tender bananas, creamy yellow calla lilies and black-leafed taros and alocasias bring a tropical look that many gardeners want at the beach. Valenti said it's important that the garden contain temperate plants for off-season interest.
What has not worked for him? A series of hybrid coneflowers have been highly prized for their novel colors, in soft oranges, reds and yellows, but of 36 varieties positioned around the garden, all but one died. He has seen coral bell varieties struggle. One named Lime Rickey "failed miserably," he said. The plantings of Adriatic bellflower were doing well until the temperature hit 95 degrees. "Half of them died," Valenti said.
Any designer working at the beach is fighting one basic reality: flatness. Gardens that don't lead you and your eye up or down a bit are not as interesting as those that do. So you have to create the illusion of gradient changes. Valenti's waterfall gushing into a pond does that, and the lack of a natural hill behind it is camouflaged by a screen of arborvitae.
Layering trees and shrubs, and mixing deciduous with evergreen plants also help to disguise the flatness while providing effective screening against one other inevitability at the seaside these days: development of the neighboring lot.