Change: A Perspective on Aesthetics and Climate in the Garden

July 9, 2019

landscape design, water mitigation, landscaping

Written by Matt Sprouse, PLA, Sitework Studios – Principal and Amy Fahmy, PLA, Sitework Studios – Landscape Architect

This past year brought us to Southern Highlands Reserve to talk about water. We were eager to once again revel in this wonderful garden, designed to inspire appreciation for the diversity of native plants of the highlands. No better example exists of a man-made landscape that blurs the lines seamlessly with the surrounding ecosystem. Yet change is always present, and as with gardens everywhere, a constant effort is required to maintain the displays amid the forces of nature. SHR works tirelessly to maintain the vision and beauty of the gardens and for the past few years this has included a mighty struggle with water.

Six months into 2019, SHR has already experienced two 100-year storm events. These storms overwhelm the existing drainage infrastructure, cutting new channels on the steep slopes and eroding plantings. Kelly and her staff hold their breath with each storm, waiting to see what losses they’ve sustained. After each storm, SHR staff work to quickly bring the garden back to a presentable state. Washed out paths, fallen trees, and uprooted plants are a weekly challenge. A garden is one of the few places where we traditionally appreciate and expect change – the change of seasons, the evolving sequence of blooms, the transition from seedling to mature specimen. SHR is now working to bring a new aesthetic component to the changes wrought by stormwater. If excessive rainfall is the new normal, can that 100-year event occur within a designed erosion management system that has both efficiency and beauty for visitors to appreciate?

Let’s consider what SHR is up against this summer. Southern Highlands Reserve rests at 4,500 feet above sea level in one of the few temperate rainforests in the Eastern U.S. The highland area of Transylvania and Jackson Counties, including Toxaway Mountain, sees some of the highest recorded rainfall in the region. Temperate rain forest classification is a minimum of 60 inches of rainfall in a year. Last year’s rain fall measurement at Southern Highlands Reserve was 130 inches.  Precipitation is a constant at the Reserve. Low cloud cover, rising fog, and the constant movement of ground water up through the trees and out the leaves (transpiration) fills the air with moisture. As the sun warms the moist summer air, cumulonimbus clouds rapidly form over the mountain and blue skies change to ominous dark gray in a matter of minutes.

Excessive rain events are with us for the foreseeable future. Through design, exciting possibilities exist to bring the wild forces of weather and the cultivated beauty of the garden together. The design of beautiful stormwater systems sounds like an oxymoron but progress is underway. It is now conventional wisdom that man-made drainage systems should recharge groundwater locally rather than dumping concentrated flow downhill. To achieve this with recurring 100-year storm events, we must fully understand the natural drainage system within the soils, rocks, and plants that hold a garden together. We can then evaluate which plants have the potential to be introduced into this local ecosystem as partners in erosion control, and from this we can move towards plant choices with nice flowers, contrasting textures, and form – classic garden design techniques. Swales, level spreaders, and catchment basins are examples of effective functional systems that disperse water near the point of origin. Filling a catchment basin with masses of plants that can thrive in wildly fluctuating water levels is an example of the new landscape aesthetic. Another is germination blankets or coir logs with planting holes that support gorgeous wildflowers on highly erodible slopes. Live stakes from shrubs with stoloniferous roots can create both fibrous root mats on stream banks and fabulous blooms for visitors.

The design of these hybrid storm water solutions requires the same artistic, creative, and inventive principles as those developed over the centuries for beautiful gardens. If “beauty is in the eyes of the beholder” the more we understand about the ecology underpinning our existence the more we find it beautiful. Take Lurie Gardens in Chicago or the High Line Park in New York City, both are “wild” meadows in the center of urban places. Both gardens would once have been visually unacceptable, but the new landscape aesthetic is clearly evident in these gardens. Each garden’s function is as beautiful to their communities as is the flowering season. As a haven for pollinators, the rough and unkempt phases of the gardens are appreciated for seed heads, nesting sites, and insect overwintering.

Southern Highlands Reserve is working to understand stormwater as an asset in the garden. Their solutions can tap man-made structures that function in harmony with natural systems. No one said it would be easy, but Southern Highlands Reserve is on the right track.