Thyrsacanthus Species, Firespike, Purple Firespike, Purple Flame

Thyrsacanthus callistachyus

Family: Acanthaceae (ah-kanth-AY-see-ee) (Info)
Genus: Thyrsacanthus
Species: callistachyus (kal-lis-STAY-kee-us) (Info)
Synonym:Odontonema callistachyum


Tropicals and Tender Perennials

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Sun to Partial Shade

Light Shade

Partial to Full Shade


Grown for foliage



Foliage Color:

Unknown - Tell us


36-48 in. (90-120 cm)


24-36 in. (60-90 cm)


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)

USDA Zone 11: above 4.5 C (40 F)

Where to Grow:

Unknown - Tell us



Bloom Color:

Magenta (pink-purple)

Fuchsia (red-purple)


Medium Purple

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Winter/Early Spring

Mid Spring

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall

Mid Fall

Late Fall/Early Winter

Mid Winter

Blooms all year

Blooms repeatedly

Other details:

Unknown - Tell us

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

From softwood cuttings

From seed; direct sow after last frost

Seed Collecting:

Unknown - Tell us


This plant is said to grow outdoors in the following regions:

Sacramento, California

Brooksville, Florida

Clermont, Florida

Daytona Beach, Florida

Deland, Florida

Delray Beach, Florida

Fort Lauderdale, Florida(2 reports)

Gainesville, Florida

Groveland, Florida

Hollywood, Florida

Key West, Florida

Lake Mary, Florida

Lakeland, Florida

Lutz, Florida

Lynn Haven, Florida

Melbourne, Florida

Miami, Florida

New Port Richey, Florida

Ocala, Florida

Odessa, Florida

Orange Park, Florida

Riverview, Florida

Saint Petersburg, Florida

Sarasota, Florida(2 reports)

Tampa, Florida(2 reports)

Titusville, Florida

West Palm Beach, Florida

Winter Springs, Florida

Baton Rouge, Louisiana

Lafayette, Louisiana

Mandeville, Louisiana

Youngsville, Louisiana

Hattiesburg, Mississippi

Blythewood, South Carolina

Saint Helena Island, South Carolina

Angleton, Texas

Austin, Texas

Boerne, Texas

Brenham, Texas

Houston, Texas

Oakhurst, Texas

Portland, Texas

Richmond, Texas

San Antonio, Texas

Shepherd, Texas

Spring, Texas

show all

Gardeners' Notes:


On Jun 24, 2015, sunkissed from Winter Springs, FL (Zone 9b) wrote:

I've had my plant for a few seasons now. Mine is in a mostly shaded area but does get some good morning and very late afternoon sun. It doesn't bloom until the later fall and early winter months, all the way through about April, unlike the red firespike that blooms in the summer to fall months. So far our coldest nights that hovered around mid 30's haven't affected it, although mine is protected by an overhead oak tree. I have successfully rooted clippings off the plant and given them away to friends. Except for twice a week irrigation, I've done nothing else, but trim it back after it is done blooming in the late spring. Hummers visit it daily through out the blooming period.


On Mar 29, 2015, GardenDolly from Orange City, FL wrote:

Purple Firespike grows well in Orange City, zone 9b. Easy to start from cuttings. Not good for cut flowers because the petals fall.


On Dec 8, 2013, vossner from East Texas,
United States (Zone 8a) wrote:

P)planted in bright shade in my garden. After 2 years, it has yet to bloom.


On Feb 11, 2013, RustyB from Mandeville, LA wrote:

Very stalky grower. Has exceeded 6 feet in my garden. I have two plants, one in deep shade, the other in filtered sun all day. The one in the shade has bloomed, though it waited until January to do so. Strange! The purple blooms are more attractive than the red species IMO.
I plan to trim them back this spring. Hope that's the right thing to do.


On Jul 17, 2007, hawkarica from Odessa, FL (Zone 9b) wrote:

This is a very vigorous plant. I started from a cutting and in just two years, it is 8 feet across and 10 feet tall. It is almost always in bloom and the butterflies and hummers love it. I have had no pest or fungus problems.


On Jan 13, 2004, htop from San Antonio, TX (Zone 8b) wrote:

San Antonio, Tx.
This plant, native to Mexico and Central America, solves the problem of having a shady area where very few plants will grow, much less bloom. In San Antonio, firespike is grown for its beautiful deep green bushy tropical foliage in the spring, summer and late fall and its magnificent purple, lavendar-purple or fuscia-pink blooms (depending upon the cultivar) from early to middle August (Zones 8a, 8b) until the first freeze. The bloom time depends upon in what Zone they are grown. In frost free zones, they may bloom all year and become much larger in size. Firespike (fire spike) can serve as a substitute for the hosta that tends to be devoured by snails and mealy bugs (pill bugs)in this area of Texas. However, I planted light green and white hosta in the foreround ar... read more