Tucked away at the end of a forest road in New York’s Putnam Valley sits an ancient lake.  It was formed thousands of years ago as a glacier carved its way through the landscape until it found its final resting place and melted into the chasm it created by its savage and slow crawl. Steep slopes that resemble vertical walls careen down to the water’s edge, punctuated by enormous boulders that one can only assume were deposited by the gargantuan prehistoric mass of ice and earth as it came to rest. 

Indian Lake is currently home to private residences, one of whom invited One Nature to improve their property. Once home to a children’s summer camp, the landscape is marked with reminders of the rich history of the property and of Putnam Valley as a whole. An access road switches back and forth across the steep slope to the water’s edge, retained by titanic boulders, to a small dock and boathouse waiting to be used in the warm summer months. The mostly grass landscape is made more interesting by its different levels, separated by short stone walls and connected by two small concrete staircases. 

The purpose of our invitation was to help our client hide some less-appealing, but important concrete walls, open the space and enhance the soft-scaping.  We did this by demolishing a section of the standing wall, building a curved stone retaining wall, and incorporating a custom wooden panel fence into a new freestanding border wall along the northern property line.  In addition, a line of five Maple trees were added along the border, and several small plantings filled in the hardscaping.

Upon arriving on the job site, our first concern was giving ourselves a clean area in which to work, weed whacking down the ground cover, then removing overgrowth and various invasive species which had been allowed to stake out territory throughout the job site. Some of the major species we removed include Barberries (Berberis vulgaris), Bittersweet (Celastrus scandens), Tree of Heaven (Ailanthus altissima), and Poison Ivy (Toxicodendron radicans). With the site trimmed down and cleared of invasives, we then spread a thin layer of compost and seeded it with White Clover (Trifolium repens) to out compete any species which escaped the eradication process.

With the area cleared of brush, we began the demolition of a wall section which bisected the space, severely limiting movement within the area. With the help of a mini-excavator, and using rock bars to break up the chunks of stone and concrete, we made quick work of the demolition, stockpiling the materials removed close by for use as fill in the future retaining wall. This practice of recycling old concrete and stone debris for use inside of retaining walls is one we’ve used before, and is much more economical, both financially and environmentally, than sending more waste off to the landfill. Similarly, our serpentine retaining wall, which conceals an existing concrete wall, allows us to leave concrete materials where they are, in the ground. 

With the concrete wall down, we began the process of building our new stone wall, first determining the path it would follow, and digging a 3-4” trench for a gravel footing to ensure drainage beneath the wall. Because the space was already dominated by rectangles and straight lines, we decided to introduce dramatic curves to give the space a sense of balance. A serpentine wall not only provides immediate aesthetic appeal, but also provides the structure with added strength as well. Complementing straight lines and shapes with curves and undulations is somewhat of a hallmark of a One Nature construction, and serves as a physical representation of our philosophy that we humans must seek to establish a harmonious relationship with our environment.

Stone wall construction is an art form, and as such, there are many different methods and schools of thought regarding the practice. Its method of construction and materials used can vary depending on its function, its method of construction may vary. The first wall we built on this job was a bit of a cross between a retaining wall and a garden wall. One function of the wall is to conceal the unattractive stone-and mortar retaining wall behind it, while also acting as a retaining wall for soil required to accommodate plants which will further obscure the existing concrete wall, over time rendering it virtually invisible. Though the existing concrete wall is still in fine condition, and therefore still bears much of the burden of retaining the slope behind it, our stone wall nevertheless exhibits all the features of a retaining wall. These features include a backward lean, into the slope, to counteract the downhill pressure of uphill materials, and the frequent use of long stones extending back into the wall, known in the trade as  “dead man” stones. Dead man stones are typically among the longer stones in a wall and will usually run a few feet back into the wall, despite sometimes not having a very large face. The purpose of a “dead man” is to anchor the stone into the slope, and, when stones are placed on top, their weight will help distribute weight further back in the wall, keeping it from leaning forward from pressure over time, or worse, eventually toppling over. 

As mentioned above, different types of stone walls call for different methods of construction. With a retaining wall, the focus is on creating tight joints in the face and on top of the wall, but the backside, which is concealed by the material the wall is retaining, can be filled with just about any hard material (except wood, which will rot) that the builder has available. This was a great place to get rid of concrete, as well as the less attractive or odd shaped stones that can be difficult to stack. For the reasons previously stated, retaining walls are typically much easier to build than freestanding walls, which, because both sides are visible, require a finished look on both the front and back. Capstones also must be the correct depth, and cannot extend back into the hillside the way they can on a retaining wall.

With our serpentine wall just about complete, we turned our focus to the line of Maple trees and the mulched planting beds in which they sat along the northern property line. With the use of an excavator, and the gracious approval of the neighbors to use their property, we were able to get a half-dozen gorgeous, 4.5” diameter Maple trees in the ground. To fill in around the Maples, we selected Carex (Carex Pennsylvanica), a sedge grass that will fill in quickly on its own, and which prefers part shade, perfect for planting at the trunk of a tree. 

Before we planted any further, we had another stone wall, as well as a fence to build along the northern property line, just beyond the line of Maple trees we had just put in the ground. This feature required no small amount of skill and ingenuity, and, in conjunction with the serpentine wall just up the hill, establishes the space as a showcase of varying, yet cohesive stonework forms.

We began by installing the fence posts, for which we used beautiful Oak 6”x6” beams.  In a couple of spots, we hit bedrock while digging holes for our fence posts. To solve this dilemma, we drilled rebar into the rock and then set the post in the hole alongside the rebar, and poured concrete, bonding the post to the rebar which was anchored firmly into bedrock. Once the posts were set and backfilled, we began to construct our stone wall around the posts, taking care to ensure that our wall tapered in, from its wide base to the top, so that all the weight would lean toward the middle of the wall, and not to either side. Once we reached our desired height of 30” on our wall, we continued securing our oak fencing to the posts. Once finished, we could then fill in around the Maple trees with Carex (Carex pennsylvanica), and then finish the area by mulching around the new grasses and trees. 

We continued to bring in plants to fill in and soften up the new landscape. We planted Mountain Mint (Pycnanthemum muticum), Carex (Carex pennsylvanica) behind the stone wall to fill out and obscure the old, partially concealed concrete walls. In stone-lined bed at the base of the wall, we introduced more Carex (Carex pennsylvanica), Evergreen Inkberry (Ilex glabra), and the pollinator attractants Ox-eyed Sunflowers (Heliopsis helianthoides), and Yellow Coneflower (Echinacea paradoxa). Along the water’s edge, we planted a border of Little Bluestem (Schizachyrium scoparium). A White Cedar (Thuja occidentalis) tree sits just inside the curved wall, standing watch with a Pussy Willow (Salix discolor) over the entire lakefront refuge and the events of the unfolding spring.