Blue Throatwort

Trachelium caeruleum

Family: Campanulaceae (kam-pan-yew-LAY-see-ee) (Info)
Genus: Trachelium (trak-ELL-ee-um) (Info)
Species: caeruleum (see-ROO-lee-um) (Info)



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

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

Water Requirements:

Drought-tolerant; suitable for xeriscaping

Where to Grow:

Unknown - Tell us


36-48 in. (90-120 cm)


36-48 in. (90-120 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)

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Full Sun

Sun to Partial Shade


Handling plant may cause skin irritation or allergic reaction

Bloom Color:


Bloom Time:

Mid Summer

Late Summer/Early Fall




Other details:

Unknown - Tell us

Soil pH requirements:

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

7.9 to 8.5 (alkaline)

Patent Information:

Unknown - Tell us

Propagation Methods:

From softwood cuttings

From seed; sow indoors before last frost

From seed; direct sow after last frost

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:

Clovis, California

Davis, California

Fairview, California

Fremont, California

La Canada Flintridge, California

Martinez, California

Norwalk, California

Oakland, California

Pasadena, California

Perris, California

Richmond, California

Sacramento, California

San Mateo, California

Santa Clara, California

Soquel, California

Warren, Michigan

Saint Joseph, Missouri

Austin, Texas (2 reports)

Vancouver, Washington

show all

Gardeners' Notes:


On Apr 26, 2011, kaydiehl from Pasadena, CA wrote:

Looks lovely in among the roses. Blue softens the contrast among bright roses that might otherwise clash. Gets tall enough to need support. I grow them through short hoops about a foot tall so I don't have to stake each individual cane. Once the roses are up and the tracheliums are well sprouted, the supports are invisible.


On May 16, 2006, gardenbeads from Warren, MI (Zone 5a) wrote:

This plant is commonly called Blue Lace flower or Blue Throatwart. It is a tender perennial and does not overwinter in Michigan but can be grown as an annual. It will grow to about 2 1/2 feet high and has a bush-like habit. It flowers continuously from summer to fall and does best in sun/part shade. A great cut flower, one of my favorites.


On Nov 22, 2002, jkom51 from Oakland, CA (Zone 9b) wrote:

Beautiful flower heads on slender stems; plant needs some staking when it gets to full 3' height. Flowerheads are fragrant, very similar to lilac with a vanilla scent. Excellent as cut flowers.