Thalia Species, Powdery Alligator-Flag, Powdery Thalia, Water Canna

My mother bought a small piece of this plant and put it in her koi pond where it grew like crazy (good crazy). She overwintered it in he...Read Morer (Zone 6) pond with a small heater in there for the past two seasons successfully. If you want to test overwintering it in your pond it would be easy to just divide it and leave part of it in the pond with the heater(/de-icer) so you won't lose the entire plant if it doesn't work the first time.

It has grown so large after two seasons of overwintering that my mom had to divide the (originally tiny) plant and she gave me a 3 ft by 3 ft section of it this year. It's currently in a large pot that I filled with soil (with water saving crystals) and didn't drill any drainage holes into. Even small brown (dead-looking) pieces that fell off while she was dividing the root system sprouted a brand new plant.

I really like this plant. The flowers may not be as showy as some other water plants, but it has great color and movement (especially on a sunny and breezy day). It grows like a champ and the color of the leaves is gorgeous.

We live outside of Boston, MA and just purchased this plant in the spring for our koi pond. Fantastic! Very prolific and the slender flow...Read Moreer stalks tower over everything.

Being in zone 5-6, I am curious if I can leave this in the pond to overwinter. I have been told that some people move them to deep water and they do fine. Others bring them in. Being so tall, it is dominating my dining room and I would prefer to leave it in the pond if that will not kill it.

Thanks.

Easy to grow and very pretty purple blooms that last a long time.

We are growing this at a high elevation in zone 7. The thalia bloomed at periods around 74 degrees this year. Appeared to not bloom at ho...Read Moret periods. Grown in full sun in water 8 inches over the top of soil level. The blooms are delicate so do not touch those as they will drop, but do not seem to be disturbed by hummingbirds. If the blooms are disturbed you miss your chance for the wonderful skin covered seeds in Fall. Those appear to be purple berries but within three weeks after picking they dry so as to remove the skin easily. Seeds are prone to mildew while fresh after picking lightly wash with a antifungicidal in a portion of water. The seeds after shelled appear to have a marbled coloring kind of like a pinto bean. The seeds should be rounded not sunken. To use seeds the next spring, scarify the seeds in spring to allow water to enter the seed for germination and plant two inches down in a pot of fertile water garden soil. Fertilize monthly with a fertilizer tablet. Use only one tablet per pot. Over fertilizing causes leaves to yellow and die. Contains a great deal of nectar. Hummingbirds love this plant dearly.

Thalia dealbata

Suitable plant for bog or pond. The leaves are lance-shaped, bluish green with purple margins. The leaves...Read More can grow to 20" long and 10" wide and are covered with a white powder, thus, the common name of Powdery Thalia.

These plants require a large pot of at least a 5 gal. size or larger. They can be grown in water up to 12" over the pot rim.

Sun to partial shade, but shelter from strong winds to keep from tipping over. In cold climates, they may be overwintered indoors as a tropical houseplant.

In the summer, Thalia has tall spikes of tiny purple flowers.