Photo by Melody

PlantFiles: Alligator Flag, Fire Flag, Red Stemmed Thalia
Thalia geniculata

Family: Marantaceae
Genus: Thalia (THAL-ee-uh) (Info)
Species: geniculata (gen-ik-yoo-LAH-tuh) (Info)

4 members have or want this plant for trade.

Ponds and Aquatics

8-10 ft. (2.4-3 m)

24-36 in. (60-90 cm)

USDA Zone 7a: to -17.7 C (0 F)
USDA Zone 7b: to -14.9 C (5 F)
USDA Zone 8a: to -12.2 C (10 F)
USDA Zone 8b: to -9.4 C (15 F)
USDA Zone 9a: to -6.6 C (20 F)
USDA Zone 9b: to -3.8 C (25 F)
USDA Zone 10a: to -1.1 C (30 F)
USDA Zone 10b: to 1.7 C (35 F)

Sun Exposure:
Sun to Partial Shade

Unknown - Tell us

Bloom Color:

Bloom Time:
Late Spring/Early Summer
Mid Summer
Late Summer/Early Fall

Grown for foliage

Other details:
Very high moisture needs; suitable for bogs and water gardens

Soil pH requirements:
Unknown - Tell us

Patent Information:

Propagation Methods:
By dividing rhizomes, tubers, corms or bulbs (including offsets)
From seed; stratify if sowing indoors

Seed Collecting:
Allow seedheads to dry on plants; remove and collect seeds

Click thumbnail
to view:

By Floridian
Thumbnail #1 of Thalia geniculata by Floridian

By Floridian
Thumbnail #2 of Thalia geniculata by Floridian

By wanda11
Thumbnail #3 of Thalia geniculata by wanda11

By kennedyh
Thumbnail #4 of Thalia geniculata by kennedyh

By Floridian
Thumbnail #5 of Thalia geniculata by Floridian

By Floridian
Thumbnail #6 of Thalia geniculata by Floridian

Thumbnail #7 of Thalia geniculata by TREEHUGR

There are a total of 9 photos.
Click here to view them all!


4 positives
2 neutrals
No negatives

Gardeners' Notes:

Positive yogadoga On Sep 26, 2010, yogadoga from Ronkonkoma, NY wrote:

this is my first season with this plant in my koi pond. I purchased this as a single baby plant on ebay . within a month it had grown dramatically to the point that I had to transfer to a 5 gallon container. according to the information I've read it grows to 6ft height, my plant is well over 8 ft high she is in stones only, no soil and in around 3 inches of water.
I live in long island , ny.

my concern is how do I winter her? do I have to cut her down in order to put her at bottom of pond? she is way too big to store inside.

Positive LuvMyGreen On Jun 1, 2010, LuvMyGreen from Clearwater, FL wrote:

i love this plant! its foliage is beatiful. very hardy and quick growing. i have mine in a pot and it sucks up water like crazy! seems to do best in half sun and half shade but see it in every type of light in the wild here in clearwater. awesome plant though. happy gardening

Positive joshz8a On Mar 23, 2007, joshz8a from z8a, AL (Zone 8a) wrote:

Last year planted this from a 6" pot into a 20" pot, and it grew so well I'll be repotting this spring into at least a 24" pot. Beautiful sturdy leaves the main attraction but enjoyed the delightful tiny flowers. Although I'd read it was a bog plant, I just gave it daily waterings in summer, weekly in winter, as with all my other containers and it did fine in full sun. josh

Positive wanda11 On Jul 9, 2003, wanda11 from Baton Rouge, LA wrote:

This plant has been very successful in my garden which is located in Zone 8b. It started out last year as a small potted plant in one of my ponds, then I moved it and planted it in the ground. This year, the original plant is larger and we have a large number of new plants that sprouted from the seeds that dropped last year.

Neutral Terry On Sep 25, 2001, Terry from Murfreesboro, TN (Zone 7a) wrote:

Thalia geniculata is slightly less hardy than T. dealbata. Its common name, Alligator Flag, may be the result of where the plant is found in its natural habitat, which is near the deeper water of the cypress swamps, where alligators are likely to be found.

Plant in shallow pond or in bogs where the soil will stay moist. It is reliably hardy to zone 8, but with mulching may survive winters outdoors as far north as zone 6. For best results, overwinter in a protected spot.

Neutral Floridian On Sep 24, 2001, Floridian from Lutz, FL (Zone 9b) wrote:

Alligator flag is a large broad leafed aquatic plant with small, delicate purple flowers. The bisexual flowers have 3 petals, 3 small sepals and hang in pairs on zigzag stems.
Its natural habitat is the freshwater wetlands of Florida and the West Indies. It blooms from around May through November.


This plant has been said to grow in the following regions:

Phenix City, Alabama
Boca Raton, Florida
Clearwater, Florida
Clermont, Florida
Melbourne, Florida
Okeechobee, Florida
Oldsmar, Florida
Port Saint Lucie, Florida
Punta Gorda, Florida
Venus, Florida
Savannah, Georgia
Spotswood, New Jersey
Ronkonkoma, New York
Georgetown, Texas
Kemah, Texas
La Vernia, Texas

We recommend Firefox
Overwhelmed? There's a lot to see here. Try starting at our homepage.

[ Home | About | Advertise | Media Kit | Mission | Featured Companies | Submit an Article | Terms of Use | Tour | Rules | Privacy Policy | Contact Us ]

Back to the top

Copyright © 2000-2015 Dave's Garden, an Internet Brands company. All Rights Reserved.

Hope for America