Symphyotrichum praealtum

Species Native to Missouri
Common Name: aster 
Type: Herbaceous perennial
Family: Asteraceae
Native Range: Southeastern to central and southwestern United States
Zone: 4 to 8
Height: 2.00 to 5.00 feet
Spread: 1.50 to 4.00 feet
Bloom Time: August to October
Bloom Description: Lavender rays and yellow centers
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Low
Suggested Use: Rain Garden
Flower: Showy
Attracts: Butterflies
Tolerate: Wet Soil

Culture

Easily grown in rich, moist loams in full sun to part shade. Often occurs in wetlands. Good air circulation helps reduce the incidence of foliar diseases. Pinching back stems several times before mid-July will help control plant height, promote bushiness and perhaps obviate the need for staking. Easily grown from seed and often abundantly self-seeds in the landscape. Plants may be cut to the ground after flowering to prevent unwanted self-seeding and/or to remove unsightly foliage.

Noteworthy Characteristics

Symphyotrichum praealtum, commonly known as willow aster, is an herbaceous perennial that typically grows to 2-5’ tall on stems clad with narrow, alternate, slightly toothed, willow-like leaves (each to 5” long by 3/4” wide). Small veins in a reticulated pattern are very noticeable on the whitish-green leaf undersides. This aster is native to moist locations including wet prairies, lake or stream margins, ditches, open woodland areas, fields and roadsides from Maine and Ontario south to Florida and New Mexico. It often grows in the wild in dense colonies. Flower clusters bloom near the top of the plant from August to October. Each flower (to 1” across) features 20-35 pale lavender (occasionally white) rays surrounding a yellow center disk which ages to reddish-purple. Flowers bloom August to October. Seeds are distributed to new locations by wind.

This willow aster was formerly known as Aster praealtus.

Genus name comes from the Greek symph meaning coming together and trich meaning hair in possible reference to the flower anthers.

Specific epithet means very tall.

Problems

No serious insect or disease problems. Some susceptibility to powdery mildew, leaf spots and rust. Taller plants may require staking or other support. Foliage tends to decline by late summer.

Garden Uses

This aster is best grown in moist areas of the landscape including borders, open woodlands, prairies, cottage gardens, native plant gardens or peripheries of water bodies, Mass or group.