Q and A: I have a piece of property with a retention pond in the front and several small wetlands in the back. I am interested in planting around these water bodies, but am unsure about where to start.
from Dr. M., in Fort Myers
The aesthetic and wildlife habitat value of ponds and retention areas can be greatly enhanced by establishing and managing desirable plants. Aquascaping is the planting of aquatic and wetland plants in and around water. The types of wetland systems that can be aquascaped include lakes, retention ponds, detention ponds, and other low-lying drainage areas.Keep in mind that it is difficult to imitate nature. Aquascaped areas may appear successful in terms of plant establishment, but may not be functioning in a natural manner.
A successful project will start with preparation.
- Determine where the normal or average waterline will be, keeping in mind that seasonal water level changes may have negative effects on plantings.
- Measure the water depth and the area of the site that is to be aquascaped. Include details about shorelines and shallow areas where work will be done.
- Excavation should be considered to improve planting sites or create planting zones that may not exist.
- Then, develop a detailed plan (with an engineering design of the area to be aquascaped) that includes the types and number of plants needed.
Design conditions can greatly enhance wildlife values and retain important functions for natural services like stormwater management. In addition, if you are attempting to create a backyard pond or wetland area it is important to consider irregularly shaped ponds with islands in the middle. A regularly-shaped pond in the form of a circle, oval, square, or rectangle will have less shoreline area, less wildlife habitat, and will be inferior to other irregular designs. Shoreline areas are essential for filtering stormwater runoff and for making areas safer for human activities. Shoreline shelves should be irregular in size and shape, at least 30 to 50 feet, and at least a 6:1 slope ratio (at six feet from the edge of the water it would be one foot deep).
Plants should be placed according to their tolerance of water depth. Most shorelines can be divided into four zones along a depth range from completely exposed to completely submerged. Each of these zones will require different plants.
- The first zone is known as the transition zone. This is the area between dry upland areas and dry lowland areas. It can be defined as the area 15 to 45 cm above the water. The transition zone is normally dry and planted with grasses. Salt grass and sand cordgrass are two good species.
- The second zone is known as the shallow zone and tends to be the area 15 cm above to 15 cm below the water. In the shallow zone sand cordgrass, blue flag iris, soft rush, and maidencane will do well.
- The third zone, the mid zone, is the area from 15 to 90 cm below water. Finally, the deep zone is found 90 to 150 cm below the water depth. In the mid zone, arrowhead, maidencane, pickerelweed, and soft-stem bulrush should prove successful.
- In the deep zone, soft-stem bulrush, spatterdock, and water lily will proliferate.
When possible, plants should come from locally grown stock. To avoid disturbing new plantings, the deeper zones should be planted first. All areas above the aquascape should be landscaped to prevent erosion and siltation of plantings. Once a shoreline has been planted, a maintenance program may be necessary to replant species that have died and to remove nuisance vegetation. Hope you can start planning and planting now!