Shoreline landscaping can have a major impact on swimming, boating and fishing in your lake. Why? Because toxins from stormwater runoff, pesticides and fertilizers can lower water quality, trigger algal blooms, kill fish and cause excess weed growth. "Lake friendly" landscaping reduces the need for pesticides and fertilizers, helps filter harmful contaminants out of runoff before they pollute your lake, and helps control erosion.
The most common shoreline landscape is a wide lawn with exotic ornamental plants leading to a bulkhead. Here are some problems with this type of landscape:
Problem: Excess Nutrients
Wide use of lawn and garden fertilizers on shoreline property can cause nutrients to build up in the water. Rain and watering can wash fertilizers out of your yard and garden and into the lake. Fertilizer buildup in the water results in rapid aquatic plant growth and algal blooms, which hamper swimming and boating activities and kill fish. Careless discarding of lawn clippings and yard debris near the lake will also cause excess nutrients to pollute the lake.
Leave some native vegetation along your shoreline. If native vegetation is gone, reduce the size of your lawn by replanting native species of trees, shrubs and ground cover. Native plants require fewer pesticides and fertilizers, and once established, need less water than exotic ornamental varieties. Create buffer areas with native plants to act as a natural filter system, trapping nutrients from stormwater runoff before they enter the lake. Dispose of lawn clippings and yard debris or start compost piles well away from the lake or nearby streams and wetlands.
Problem: Excess Toxins
Pesticides commonly used around homes and gardens (such as diazinon, dursban and orthene) and herbicides (such as Weed and Feed and RoundUp) can cause serious damage to fish, wildlife and people when they get in the lake water. They may be blown directly into the lake when applied on a windy day or washed off plants and soil by rain or watering. Improper storage and disposal of these chemicals also can pollute the lake.
Always read labels carefully and avoid using pesticides and herbicides when ever possible, especially on windy days. Use pesticides only when you actually see a pest. Dispose of unused pesticides and containers at the local hazardous waste disposal site.
A bulkhead is not the best or only way to prevent erosion. Bulkheads create unnatural dropoffs that can be dangerous, especially to children and the elderly. They also interrupt natural shoreline vegetation.
Planting and maintaining natural vegetation instead of constructing a bulkhead will control soil erosion and runoff, provide a more gradual transition from yard to lake, help beautify your lake and enhance wildlife habitat.
Problem: Canada Geese
Lakeside lawns encourage nuisance populations of Canada geese, who like to feed in short grassy areas. Bird feces on docks and lawns can contribute harmful nutrients to the lake water, in addition to being unsightly, unsanitary and unsafe.
Replace lawn next to the lake with a six to eight-foot-wide buffer zone of low-growing plants. Consider placing a path through the buffer zone for lake access to a dock or gravel beach. Many plants are suitable for this area of wet soil, including salal, Ajuga reptans, Vaccinium vitis-idaea, Cotoneaster dammeri and Rubus tricolor. For the gardening enthusiast, the buffer zone is an ideal area for a perennial flower or herb garden or a bed of wildflowers.
Lake Friendly Landscape Plan
A good landscape plan protects water quality and encourages native plants, fish and wildlife close to shore. Remember that encouraging shoreline habitat doesn't mean building a barrier of native vegetation between your home and the lake. A balanced approach to waterfront landscaping retains natural habitat and reduces pollution and erosion, while also meeting your aesthetic and access needs.
In this example, two neighbors have worked together to create native plant zones. The following are descriptions and recommended plants for each zone.
Riparian Zone - This zone extends about two feet up the bank from the edge of the lake. Fluctuating water levels and the wave action from boats and wind impact this zone. Plants here must tolerate wet soils for long periods and have deep root systems to minimize erosion. Low-growing plants are best, so the view from your home or deck is unobstructed. Examples of plant varieties suitable for this zone are: lady fern, sedges (many species), and blue flag iris.
Lower Bank - This two to 10 foot zone is adjacent to the riparian zone. The soil here tends to be moist but not wet. Your plan for this zone should include at least three shrubs (such as red osier dogwood, red elderberry, and evergreen huckleberry) and two ground cover varieties (such as lady fern, bunchberry, and sword fern).
Upper Bank - This zone extends from the end of the lower bank zone toward your home. The landscape here should include at least three shrubs (such as serviceberry, mock orange, and red flowering currant) and two ground cover plants (such as salal, sword fern, and pig-a-back).
Mixed throughout the upper and lower bank zones should be at least two varieties of shade trees and two types of shade and cover plants to create a multi-layered canopy. Some good choices for shade trees are: chokecherry, Oregon ash, and western hemlock. For shade and cover: vine maple, western crabapple, and hazelnut.
Article reprinted by permission. Article written by Mary Jo Buza, Thurston County Community and Environmental Programs.
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