It might look like a Canna…It might act like a Canna, but Thalia dealbata is definitely not a Canna. Its solid green leaves are the dead give away. The two may have similar shaped stems and foliage, but you won’t see rainbow shades of Thalia or fluorescent blooms. What you will see are magnificent stalks that frame the edge of a pond like no other perennial. What it lacks in color, it makes up for in hardiness.
Thalia is so easy to grow that you see it in many medium sized ponds. It might look somewhat tropical, but can withstand a winter of minus 20 below. Most people buy Thalia for its lush foliage, but don’t count out the blooms. Unusual-looking long purple flowers appear in mid to late summer. The stalks reach up to six feet tall and spread very fast to give the back of your pond a lush appearance. And will even provide somewhat of a screen between you and your neighbors.
After the first year, divide Thalia regularly, so the roots don’t get pot bound. Plant it in an aquatic soil-less media or a mixture of 100 percent ground clay(unscented kitty litter) with a layer of sand on top. Make sure you find the widest pot you can because this is one fast spreader. And you’ll want to place the container in no more than six inches of water. Thalia is a heavy feeder. So if you can’t provide it with enough fish waste, you might want to invest in some aquatic fertilizer.
Thalia is native to parts of the south east United States as well as Argentina and the West Indies. Most pond stores carry this water garden staple. It may not offer a lot of fancy colors but Thalia’s green leaves stay true long after the first frost. When you see them turn brown, be sure to cut the stems down to the water line. If you don’t they will be more difficult to remove in the spring. Over time, the stalks become very woody.
Those who live in a colder climate can always over winter Thalia as a house plant or in a green house. Just don’t let up on the watering! And if you don’t have a pond, this water lover will thrive in a very moist boggy area.
If you want to pair Thalia with another plant, you might want to consider… (you guessed it) a Canna.