Easy on the Environment
Environmental design is no longer an elite service reserved for the privileged few. More and more people — around 50 million in the United States, according to California researchers Paul Ray and Sherry Ruth Anderson — have strong environmental values. High population rates, booming housing markets and an increasing awareness of the environment make this the best time to join the cadre of green industry professionals who are embracing environmentally sound practices while serving the environmental niche market.
Sketching to scale and calculating costs are only the beginning to a successful landscape design. Environmental landscape best management practices require finesse and holistic thinking to successfully implement. You must adopt horticultural technical information to fit your own locale. You also have to consider natural resource data and issues. Artistic renderings must result in beauty for the client. And good business practices must be woven through the whole process.
The customer consultation is your first and best opportunity to establish a meaningful relationship between your company and your customer. Interview clients to discover what they most value about their landscape and environment. Ask people what they like and dislike about their landscape and request specific examples. Keep in mind the customer may not be accustomed to answering such questions and may need to respond to your questions instead. For instance, you could ask, “Do you have concerns about water quality, soil erosion, pest control, weeds or wildlife?” This question is filled with prompts for the customer.
Finding out what plant material combinations the residential customer prefers can be equally difficult. Rarely does the non-horticultural homeowner have a fluent vocabulary to discuss form, structure and views. One way to quickly determine preferences is to ask the customer to show you photos (either snapped with a camera, clipped from a magazine or tagged in a book). It also helps if you bring photos with you. Ask what they specifically like and dislike about each photo. Never assume the customer likes or dislikes the same thing for the same reason that you yourself do.
Another communication must for a successful environmental design calls for you to thoroughly research, record and file all information concerning covenants and local landscape ordinances. Many jurisdictions have local ordinances in effect to protect native vegetation along shorelines. Other locations have strict tree-removal and tree-replacement guidelines.
As you may not be involved with the actual maintenance following design installation, it's essential for you to communicate the specific maintenance required. List the steps necessary to sustain the landscape, including mulching and irrigation specifics.
When selecting plant material, select the genera, species, cultivars and varieties that exhibit pest resistance and are well-acclimated to the heat and cold temperatures of your area. Remind your customers that plants with high pest resistance are less likely to attract severe pest infestations, but are never 100-percent pest free.
Sources for discovering pest resistant plant material are varied across the country. In South Carolina, the Urban Tree Species Guide, produced by Clemson University Extension Service and the South Carolina Forestry Commission, lists recommended trees for South Carolina and rates their pest resistance as high or medium. Check with your local university Extension Service or your State Forestry Commission for lists of pest-resistant plants, as pest-resistance varies with the location.
If your customers express pleasure with the existing wildlife presence in their landscape, you may wish to recommend keeping the native plant material, as it may be providing suitable habitat for the winged, webbed or hoofed inhabitants. Riparian buffers need to be large to serve as suitable nesting or breeding sites. Some natural resource agencies call for designating a 100-foot buffer width for wildlife habitat and 35-foot buffer widths on both sides of a body of water for water quality protection. Leave native vegetation on shorelines and slopes to avoid soil erosion issues.
Create large planting beds rather than solo holes, whenever possible. In clay textured soils, plants particularly benefit from the larger disturbed area of a planting bed because roots can penetrate disturbed or tilled soil easier than they can penetrate undisturbed clay. Planting beds in sandy soil areas are also ideal if the organic matter content of the soil needs to be increased. If you need to amend the soil, do so with the guidance of a professional soil test. Remember to always amend a much larger area; one a plant will grow into, rather than a small space, as water flows differently through different textured soils. You want your plants to experience uniform water retention and drainage.
Design landscapes with the mature plant in mind. Give plants plenty of room to grow, both above ground and below. Roots often spread far beyond the drip line of a tree and are usually located in the top 12 inches of the soil. Do not select plants that require frequent pruning in order to fit a space. Select the right plant for the right place by matching the plants needs and the site conditions. Consider issues of space, sun exposure, moisture and soil types.
Conserve energy with the environmental landscape design. In summer, allow plants to shade roofs, windows and walls. Use trellises to keep vines from making direct contact with wood, walls or mortar. Place deciduous trees, not conifers, on the south side of houses or buildings. Deciduous trees allow sunlight to warm the walls of the structure in the winter, which reduces heat requirements.
Customers frequently ask for color under their large trees. You should explain that adding new plants frequently causes stress to existing mature trees due to root damage and increased competition for water and nutrients. Suggest alternative design responses. One solution is to place containers of flowering plants under trees that receive drip irrigation in their pots. Another approach is to design separate beds of color either well in front of or behind the tree bed. These color beds deliver a visual mass of color without compromising the tree roots and overall plant health.
WATER QUALITY AND QUANTITY
Many environmentally conscious customers request landscapes that require no irrigation. Remind them that all plants need water until they become established. Temporary drip systems are sometimes the best solution, even for the xeriscape (drought tolerant) garden.
No environmentally savvy homeowner wants to see an irrigation system operating during rainfall. By calling for a rain sensor to be installed with the irrigation system, you will be helping your customer save money and save water. Recommend in your irrigation specifications that sprinklers come on in the early morning. This reduces loss of water to evaporation and also reduces the likelihood of fungal development.
Design with porous pavement whenever possible. Porous pavement allows the water to soak into the ground before it reaches a body of water. This simple addition to the design helps protect groundwater from contaminants. Berms, swales and bioretention areas also serve to slow water down before it reaches a body of water (including groundwater), likewise protecting the groundwater from contaminants.
Protecting large trees on a client's site should be a priority of your design. Large trees tend to increase property values and are often cited as increasing the quality of life for viewers. Large trees also slow water runoff and filter pollutants before they reach a water body. Frequently, tree roots are damaged during construction projects due to trenching, soil compaction or grade changes. Decline or death can take three to five years — sometimes even longer — to fully exhibit itself.
Protect large trees from construction damage by creating installation guidelines. Prohibit any trenching in the root system area. Trenching damages tree roots, which makes a tree susceptible to a host of health stresses including pathogen invasion. Severing tree roots may also result in an unstable tree that may topple and be a hazard. Call for 3 inches of mulch over the entire root system area to reduce soil compaction from increased traffic. Require restrictive tape to be placed well beyond the root zone (usually beyond the drip line) to prohibit vehicular and pedestrian traffic above the roots; and plan routes for vehicles and workers that lead them away from specimen trees.
Vegetative mulch is a valuable ingredient in an environmental landscape and has many benefits when it is properly applied in the landscape. It increases the organic matter of the soil as it decays; it reduces weed seed germination; it helps retain soil moisture; it keeps soil temperatures from rapidly fluctuating; it keeps leaves and stems clean by reducing soil splash during rain or watering; and it is aesthetically pleasing. Call for 3 inches of vegetative mulch over the root zone of plants and covering planting beds. Do not allow the mulch to touch the stems or trunks of plants.
“Volcano” mulching will instantly sabotage an environmental landscape. “Volcanoes” occur when mulch is piled up against the stems or trunks of the plants. Fungal decay may occur when mulch is in constant contact with plant tissue due to the moist environment and reduced oxygen. Properly applied mulch never touches the stems or trunks of the plants; it stays at least 1 to 3 inches away from the plant.
PRACTICE MAKES PERFECT
Environmental landscape design best management practices will continue to evolve and mature. A. J. Downing, in 1841, taught Americans to value “the picturesque,” or striking, irregular, spirited forms in the landscape as well as the traditionally “beautiful” soft flowing forms. Now, in 2005, we must embrace a third factor: environmental stewardship. Population increases and the resulting development demand response by the green industry. By developing and implementing environmental best management practices, we will be stewarding natural and enhanced beauty for generations to come.
Ellen A. Vincent is an environmental landscape specialist at Clemson University (Clemson, S.C.).
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