Southern Star, Tweedia 'Heavenborn'

Oxypetalum coeruleum

Family: Asclepiadaceae (ass-kle-pee-ad-AY-see-ee) (Info)
Genus: Oxypetalum (oks-ee-PET-al-um) (Info)
Species: coeruleum (ko-er-OO-lee-um) (Info)
Cultivar: Heavenborn
Synonym:Tweedia coerulea
Synonym:Amblyopetalum coeruleum
View this plant in a garden


Tropicals and Tender Perennials

Vines and Climbers

Foliage Color:


Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Drought-tolerant; suitable for xeriscaping

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


12-18 in. (30-45 cm)

18-24 in. (45-60 cm)

24-36 in. (60-90 cm)

36-48 in. (90-120 cm)


15-18 in. (38-45 cm)

18-24 in. (45-60 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)

Sun Exposure:

Sun to Partial Shade


Unknown - Tell us

Bloom Color:

Light Blue


Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall



Other details:

May be a noxious weed or invasive

Soil pH requirements:

Unknown - Tell us

Patent Information:

Unknown - Tell us

Propagation Methods:

From softwood cuttings

From seed; direct sow outdoors in fall

From seed; sow indoors before last frost

From seed; direct sow after last frost

Self-sows freely; deadhead if you do not want volunteer seedlings next season

Seed Collecting:

Allow pods to dry on plant; break open to collect seeds

Properly cleaned, seed can be successfully stored


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

Anniston, Alabama

Toney, Alabama

Clayton, California

Fullerton, California

Los Angeles, California

Deland, Florida

Snellville, Georgia

Eupora, Mississippi

Hattiesburg, Mississippi

Elizabeth City, North Carolina

Atlanta, Texas

Austin, Texas

Brenham, Texas

Garland, Texas

Houston, Texas

show all

Gardeners' Notes:


On Aug 12, 2009, derbeh from Los Angeles, CA (Zone 10a) wrote:

although this plant is not as close a relative to common milkweeds as some other cultivars, the first year i had my plant, it was feasted upon by a monarch butterfly larva, which subsequently molted (off-plant) into a beautiful butterfly. i guess this plant is closely enough related to be tasty to the butterfly larvae.


On Aug 7, 2008, vossner from Richmond, TX (Zone 9a) wrote:

aka blue butterfly weed. just purchased it, no experience yet.
08/2009 Be very skimpy w/ water; it rots easily. Mine is planted inground, bright shade and now that I know it likes it dry, it is doing well. Flowers are a unique blue and beautiful. I'm noticing butterflies hovering around. I would not call it invasive in my garden.


On Aug 12, 2002, lupinelover from Grove City, OH (Zone 6a) wrote:

Plant was purchased already blooming; somewhat leggy. Failure to remove seedpods in a timely manner will result in the death of this plant. Failure to dispose of seedpods will result in many germinating the following season which will probably not be as good as the hybrid desired.