Water gardens add beauty, tranquility, and wildlife habitat to landscapes. Like other forms of landscaping, water gardens involve plant selection and spacing, weed management and regular maintenance. Aquatic landscapes differ from conventional gardens in the types of plants (emergent, floating leaf) and weeds (algae) and ongoing management (water quality versus soil). An additional possibility with water gardens is the opportunity to stock fish or turtles, while attracting native aquatic wildlife.
Planning for successful water gardens requires consideration of climate and containment. Along with selecting plants appropriate for the temperature extremes of the region, well-designed ponds are built to protect against flooding and are isolated from discharging to public waterways or wetlands. Just as traditional gardeners consider the growth and spreading habits of their plants, water gardeners should use native species or exotics that are not considered invasive.
Design
Water gardens vary in design and size, from small container gardens to elaborate ponds with recirculating water and multiple filtration. Your aquatic garden choice depends on many factors unique to the climate, the topography and existing landscaping in your property, nearby public waters and personal preferences.
Choosing the right species
There are many species of water garden plants, including the ever popular water lilies, emergent plants such as arrowhead, and submerged species like tapegrass. Beyond their ornamental appeal, aquatic plants play a role in regulating nutrients in your garden, helping to minimize nuisance algae and reduce your maintenance duties.
The combination of species in your water garden will depend on the climate, particularly extreme temperatures. Other factors include the size of your aquatic garden, shading by trees or buildings, water source and depth, and whether you plan on adding fish.
Maintenance
Water gardens require maintenance like their vegetable and flower counterparts. The level of maintenance varies with pond design, size and species selection, and should be considered in your early planning. Your primary concern is maintaining water quality for the health of pond plants and animals, along with minimizing growth of undesirable algae. Like other gardens, many aquatic species have seasonal die-offs in the colder parts of the U.S. that may require attention.
Protect the Environment
In considering plants for your water garden, choose species that are either native to your area or are not considered invasive. Many plant species are regulated by the states or the federal government. These may go by the names of “noxious plants” or “nuisance aquatic species.” Consult the combined state and federal list of regulated and prohibited aquatic plants for more information. The Aquatic Nuisance Species Task Force website has information on invasive species, including aquatic plants.
Purchase plants from reputable sources; scientific names should be included on the product description so you can determine whether they are invasive or regulated in your state. Other resources are your department of agriculture, natural resources agencies, agricultural extension office, and local garden clubs and water garden societies.
Some plants may come with hitchhikers in the roots or the soil. These accidental plants and animals may be invasive, so it’s a good idea to check for unwanted visitors before planting.
If you have to remove any of your garden inhabitants, dispose by placing plants in plastic bags and discarding them in the trash. For unwanted fish, visit Finding a New Home for your Pet.
Design your water garden for unusual rain events to avoid releasing plants and animals to nearby waters. Berms and swales or other physical barriers may be key features for flood prone areas. See Water Garden Design for more information.
Additional Resources
For additional websites of interest on design, construction, species selection and regulations, click here.
Introduced Species in the USA
The United States Geological Survey has a database and maps of non-native aquatic species that have been found in the United States; for more information on species that have been found in your state, click on the map.