by Katie Bartling
Backyard aquatic gardens and small pond structures are gardens where water is the dominant element and there is a strong focus on the emergent, submerged and floating plant community. These areas can provide many benefits within the landscape in terms of water quality improvement, wildlife habitat and stormwater management. Oftentimes, however, we overlook them as being a part of the broader landscape and instead think of them as isolated pocket gardens that only provide beauty and tranquility.
Pollinator and Bird Garden, Penn State Arboretum, https://arboretum.psu.ed
Backyard aquatic gardens are certainly part of the surrounding ecosystem, and to an extent receive inputs and outputs of runoff, sediment and nutrients. At the very least they can be thought of as an element of stormwater collection and management. At most, they can provide a multitude of ecological benefits that assist in filtering, recycling and retaining stormwater alongside sediment and nutrient capture. In addition, aquatic gardens can provide important wildlife habitat, stop-over sites for migrating birds, and habitat for a variety of native amphibians, fish and pollinators.
Backyard aquatic garden ecosystem. Photo: Katie Bartling, Steve Ember
When aquatic garden design and management are not aligned with the goal of providing ecological uplift, there are potential impacts to adjacent natural areas through the accidental escape of non-native invasive species and alterations to water quality and/or temperature if aquatic gardens overtop into nearby streams. There is good news though, because when managed and maintained properly, these spaces can actually benefit the surrounding environment while at the same time maintaining traditional backyard aesthetics.
The installation of appropriate vegetation coupled with consistent water quality and nutrient management are key to maintaining a sustainable aquatic garden. Vegetation additions prevent soil erosion, mitigate the effects of stormwater runoff and provide wildlife habitat, while also buffering nutrients in and out of the pond system. Submerged or floating aquatic plants (alongside water aeration) assist in oxygenating the water, improving water quality, and providing habitat for a variety of aquatic organisms. This makes the placement and selection of vegetation an essential component to aquatic garden design.
To provide increased benefits to wildlife and the surrounding ecosystem, a selection of native plants are ultimately meant to substitute the non-native or invasive vegetation often chosen for backyard aquatic gardens. Invasive species in small aquatic gardens become problematic as the invasives can escape to surrounding aquatic areas, grow rapidly, out-compete native plants, create management issues and smother the water surface leading to a decrease in the dissolved oxygen content in the water column.
Through reimagining the variety of ways aquatic plants interact with and contribute to our personal outdoor space, we are able to turn what was once thought of as an isolated backyard garden into a support system for biodiversity and water quality on a broader scale.
Pond Vegetation community at Kenilworth Aquatic Gardens, Washington D.C. Photo: Katie Bartling
Aquatic garden with wetland biofilter, pump, aeration and submerged potted plants. Photo: Katie Bartling, Steve Ember
Highlighted below are a variety of native alternatives to invasive aquatic species. These native species will support the surrounding ecosystem, while also providing aesthetic and seasonal interest in an aquatic garden.
Submerged and Floating Vegetation
Emergent and Fringe Vegetation
Backyard Aquatic Garden Examples
Aquatic garden with elevated wetland biofilter, pump, aeration and submerged potted plants. Photo: K. Bartling, Steve Ember
Pond Vegetation community at Kenilworth Aquatic Gardens, Washington D.C. Photo: Katie Bartling