Blue Boy Clematis vs Smooth Aster - TreeTime.ca

Blue Boy Clematis vs Smooth Aster

Clematis integrifolia Blue Boy

Symphyotrichum laeve

NOT AVAILABLE THIS SEASON - MIGHT RETURN

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Blue Boy Clematis
Smooth Aster

Blue Boy Clematis is a cold-hardy, fast growing, woody climbing vine. Hundreds of stunning steel-blue bell shaped flowers adorn the vine throughout the summer that droop and appear to hang in the air. The fibrous stems spread and create a fan-like symmetry shape.

This species will do best with support from a trellis, fence, or even other shrubs or tree stumps.

The Blue Boy Clematis was developed in Manitoba, Canada in 1947 by famous breeder Frank L. Skinner by crossing C. integrifolia x C. viticella, but it didn’t gain popularity until the 1990’s.

Smooth Aster is a native perennial wildflower known for its violet-blue, daisy-like flowers. They bloom later in the season, from late summer to early fall. The flowers attract a variety of pollinators, including bees, butterflies, and other beneficial insects. It also serves as a host plant for the Silvery Checkerspot (Chlosyne nycteis) and Pearl Crescent (Phyciodes tharos) butterflies, further enhancing its ecological value. This easy-to-grow wildflower is well suited for native wildflower gardens, pollinator gardens, and naturalization projects.

The Smooth Aster’s non-aggressive root system allows it to spread slowly, and it is more likely to reproduce by seed, which can be controlled through deadheading.

Blue Boy Clematis Quick Facts

Smooth Aster Quick Facts

Zone: 2b
Zone: 3a
Height: 3 m (10 ft)
Height: 0.9 m (3 ft)
Spread: 0.6 m (2.0 ft)
Spread: 0.6 m (2.0 ft)
Light: partial shade, full sun
Light: partial shade, full sun
Moisture: normal, wet
Moisture: dry, normal
Growth rate: medium
Growth rate: very fast
Life span: medium
Life span: short
Suckering: medium
Suckering: none


Flowers: steel blue
Flowers: purplish-blue; daisy-like
Bloom time: late summer to early fall
Hybrid: yes
Hybrid: no
Catkins: no
Catkins: no


Native to: AB, BC, SK, MB, ON
Other Names: glaucous aster, smooth blue aster