See our step-by-step instructions to create a water garden like the one below. Remember to keep at least 40 percent of the water surface free for the sunlight to penetrate.
Materials Here's what you’ll need to get started on your water container garden.
• Watertight basin—Try a half whiskey barrel, vintage bathtub or sink, concrete trough or a galvanized livestock tank. Choose a basin that’s at least 12 to 15 inches deep with a diameter of 24 to 36 inches.
• Topsoil — Use a heavy topsoil (not potting soil) that contains clay.
• Aquatic crates — These plastic crates have lattice sides that allow roots to penetrate into the water and exchange gases and chemicals. Match the crate size to the size and type of plant.
• Granular aquatic fertilizer — Maximize plant growth and health by fertilizing these heavy-feeder aquatic plants.
• Pea gravel — Hold soil in place with pea gravel (and not crushed limestone, which will change alkalinity of the soil and water).
• Clay pots or bricks — Place beneath aquatic crates for the desired water depth.
• Aquatic plants:
Water lily. For the biggest show and most blooms, choose a tropical variety such as the day-blooming Nymphaea ‘Pink Platter’ in our container. Alternatively, consider a night-blooming tropical to enjoy flowers in late afternoon through the evening.
Oxygenator. Submerged plants like fanwort (Cabomba caroliniana) help clean the water and add oxygen.
Floating plants. Water hyacinth (Eichornia crassipes) and other floating plants provide protection for fish and shade to minimize algae bloom.
Bog plants. At 3-5 feet, an umbrella palm (Cyperus alternifolius) adds height to the water container garden. Other options include papyrus and colocasia.
Step 1: Choose a sunny location (minimum six hours of sunlight) for the container garden, and fill the basin with water. Aquatic plants are heavy feeders, so be sure to add granular fertilizer to the topsoil before filling the crates.
Step 2: In a 9-inch square crate, dig a hole in the soil and plant the water lily. Add water and firm the soil around the plant.
Step 3: Add a half-inch layer of pea gravel to hold the soil in place.
Step 4: Slowly submerge the planted crate beneath the surface of the water and rest it on the floor of the container.
Step 5: Repeat the same steps to plant the umbrella plant in an 8-inch circular crate. Submerge it in the water, this time only 1 inch deep, using a clay pot or bricks to raise the crate to the correct level.
Step 6: Float water hyacinths on the surface of the water.
Step 7: Plant the fanwort in an 8-inch circular crate and fully submerge it in the basin.
Step 8: Add more water to fill the basin. Initially the water may turn cloudy with algae, but it should clear in a couple of weeks. To maintain the container water garden, weed and prune water plans as needed, especially aggressive floating plants.
Remember to put your water container garden where it will get at least six hours of sunlight a day, and enjoy!
Resources One Midwest water lily supplier is William Tricker, Inc., of Independence, Ohio, which bills itself as "America's oldest water garden specialist est. 1892." tricker.com