Not considered a true canna, the water canna resembles one with its leaf structure.
The plant is hardy but exotic looking with its broad, bold upright leaves,green with a small maroon spot at their base.
Growing to more than 3 feet, the plant is relatively easy to keep, especially in pots.
If you do grow this plant directly in the pond, be aware that it grows best in zones 8 and below for it is a sub tropical.
The water canna makes a great addition to the pond as a perennial border, blooming much longer than the land variety canna.
They grow well in very moist soil with the crown submersed.
This plant is a native of Florida, growing to a height of 4 feet with medium green leaves, it will grow even with the crown submersed in 10-12 inches of water. The flower is yellow and resembles a daffodil, blooming prolifically in the spring and then not as much in the summer heat.
There are a few species of Canna, among them the Longwood hybrid, with its blue-green leaves and a bit more cold tolerant than the Canna glauca, and depending on the variety, the color can range from butter yellow to orange to peach to bright red.
Since water canna is a tropical plant, bring it in for the winter months in the zones above.
The plant requires 4-6 hours of sunlight to flower, adding some fertilizer will also encourage flowering.
Winter over either by storing the rhizome in a ventilated container with sand and peat moss, kept damp, at temperatures above 65 degrees, or bring the entire plant inside, keep it warm, in sunlight as much as possible and water frequently.
In both scenarios you can bring the pots back to the pond in the spring once the water temperature reaches 65 degrees.
Insect and rust can be controlled by cutting the plant back to the crown, or in the case of Aphids, simply spray with a strong jet of water.
If any infestation requires stronger measures, such as insecticide, be careful to remove the plant from the pond prior to such use.
With jus a little care, your pond and you will enjoy the colorful aquatic plants.