A pondlike tub filled with water-loving plants can form a cool oasis on even a small deck or patio.
Tub garden on deck features big arrow-shaped leaves of Xanthosoma sagittifolium, shorterXanthosoma violaceum, and grasslike Carex morrowii 'Variegata' and Phalaris arundinacea.
Properly placed, a container water garden can reflect the blue of the sky and the colors of nearby plants. And don't be surprised if your aquatic garden doubles as a birdbath. Especially during hot spells, birds may visit to drink and preen among the leaves.
To introduce water-garden refreshment into a container collection, you'll need a leakproof container, water plants in plastic pots, and a few goldfish or mosquito fish to keep the water free of insects.
Almost any large container will work, but to house a standard water lily or lotus you'll probably need one at least 18 inches across; a 25-gallon container is a good size. If the container you choose isn't waterproof, you'll need to line it with a flexible pond liner (PVC or EPDM), pleated to fit. Or you could hide a watertight tub inside the more attractive "show" container you've selected.
You don't have to limit yourself to commercially available tubs for water gardens. You might consider using a ceramic urn or a wooden half-barrel (scrubbed and lined)--or a cast-iron soup kettle, a terra-cotta pot, a metal watering trough, or a sturdy plastic tub (some look like terra-cotta).
Choosing Water Plants:
How many plants you can use depends on the size of your container. One water lily per square yard of surface area is plenty, along with a few bunches of oxygenating plants or grasses. For smaller containers, try dwarf water lilies or grasses.
Don't crowd too many plants into your water garden. Let the water show, too. A combination of opposites--small and large plants, tall and short ones--can be the most pleasing to the eye. When you buy your plants, ask about their requirements for overwintering in your climate zone.
How to Proceed:
Position your container where it will get at least 6 hours of sun daily. A water-filled 25-gallon container weighs more than 200 pounds--make sure your chosen spot can bear its concentrated weight. Then follow these steps:
1. Fill container about two-thirds full with water.
2. Position your plants, in their pots, in the water so that pot tops will be 6 inches or more under water. (Adding an inch of sand in the top of your pots will help keep the soil from floating out.) Some plants do best if only partly submerged--set pots on bricks or upturned pots. Free-floating plants don't need to be potted. (Ask about your plants when you buy them.)
3. Fill the tub the rest of the way with water.
4. Add goldfish or mosquito fish.
Keep the water level topped, remove floating debris, and cut off dead leaves on an ongoing basis. About once a year, drain the container and scrub it out with a solution of 4 parts water to 1 part bleach. Rinse well.
A Home for Fish:
An 18-inch-diameter container can accommodate about four fish. To make your fish feel at home before releasing them, place them--still in their plastic bag--in the water garden for about 20 minutes. Make sure the water will not be too hot for the fish.
Don't overfeed your fish--you could disturb the ecological balance in your pond. In cold climates, move fish to an indoor aquarium during the winter.
Popular Water Plants:
● Arrowhead (Sagittaria latifolia): White flower spikes, arching leaves; submerge pot.
● Dwarf papyrus (Cyperus isocladus): Long, narrow leaves and flowers; submerge pot.
● Horsetail (Equisetum hyemale): Rushlike, jointed hollow stems; submerge pot halfway.
● Japanese Iris (Iris ensata): Velvety blooms, sword-shaped leaves; submerge pot halfway. Remove pot from water during plant's dormant season.
● Lotus (Nelumbo): Showy flowers, big round leaves above water; submerge pot.
● Umbrella plant (Cyperus alternifolius): Spreading leaves; submerge pot.
● Water hyacinth (Eichhornia crassipes): Violet flowers, floating leaves; free-floating. (Don't turn loose in natural bodies of water.)
● Water lily (Nymphaea): Showy flowers, round floating leaves; submerge pot.