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Azure Aster

Symphyotrichum oolentangiense (sim-fy-oh-TRY-kum u-len-tan-jee-EN-see)

Family: Asteraceae Unknown Herbaceous (1-3 ft)

Skyblue aster is an herbaceous perennial in the aster family (Asteraceae) that is native to eastern North America but not North Carolina. Its primary range is in central United States. In its native habitat, it can be found growing along roadsides, prairies and open woods in mesic to dry conditions on sandy, clay or rocky soils. Symphyotrichum comes from the Greek words symph and trich meaning coming together and hair which refers to the flower anthers. The species name, oolentangiensis, refers to the Olentangy River in Ohio where it was discovered. It prefers full sun and is adaptable to a variety of soils if it is well-drained. Skyblue aster only requires average watering. The plant can reach 2 feet tall and wide. The blue to lavender daisy-like flowers bloom in the fall. The flowers are usually sparsely arranged on the multi-branched upper stems creating a cone or vase shape. Sometimes the flowers are densely clustered which causes the plant to arch. Skyblue aster is endangered in some native areas due to over mowing of the prairies and roadsides. It is a showy fall-blooming flower which is easy to grow. It is non-aggressive even though it self-seeds and spreads by rhizomes. It is drought-tolerant and can even grow in shallow-rocky soil. It is more sun-tolerant than other blue-violet asters. It is an erect, dense clump with 1 to 5 or more stems that grow well in meadows, rock gardens or perennial borders. It is valuable for prairie restoration projects. Skyblue aster attracts butterflies, native bees, skippers, and wasps. Insects, Diseases, and Other Plant Problems: No known serious insect or disease problems. It may develop powdery mildew if there is poor air circulation. More information on Symphyotrichum .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 63 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (1-3 ft) Optimal soil pH Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Full plant profile

Growing Conditions
Plant type
Herbaceous Perennial; Wildflower
Life cycle
Perennial
USDA zones
3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Light
Dappled Sunlight (Shade through upper canopy all day) | Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Loam (Silt); Sand; Shallow Rocky
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Occasionally Dry
Available space
Less than 12 inches
NC region
Mountains; Piedmont
Mature size
Height: 2 ft. 0 in. - 2 ft. 0 in. | Width: 1 ft. 6 in. - 2 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
4 - Herbaceous (1-3 ft)
Form & Appearance
Habit / form
Clumping; Erect
Texture
Medium
Foliage
Deciduous
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Alternate; Rosulate
Leaf shape
Lanceolate; Oblong; Ovate
Leaf margin
Entire; Serrate
Leaf feel
Rough; Smooth
Leaf size
3-6 inches long, 1-3 inches wide
Hairs present
Yes
Leaf detail
The lower leaves are heart-shaped, thick, and serrated. They have winged stalks and usually wither when flowering. The leaves become more narrow with entire margins as they ascend the stem. They are smooth on top and short-hairy on the bottom. The loose tuft of basil leaves are semi-evergreen.
Flower color
Blue; Purple/Lavender
Flower value
Showy
Flower form
Panicle
Flower shape
Radial
Flower size
< 1 inch
Flower detail
The panicle of flowerheads with 10 - 20 daisy-like blue rays and yellow center is 1/2 - 1 1/2 feet long. It blooms from August to November. The flowers are usually sparsely arranged on the upper stems, but occasionally form a dense cluster. Individual flowers are 1/2 to 1 inch across.
Bloom time
Fall; Summer
Fruit color
Purple/Lavender
Fruit type
Achene
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
The fruit is a cypsela but is often referred to as an achene. The seed has light brown or rose-tinged hairs to enable wind distribution.
Stem color
Green; Red/Burgundy
Stem detail
The rough-textured stems are erect with many branches in the upper plant. May have a few hairs.
Wildlife & Ecology
Native status
Unknown
Origin
USA
Distribution
Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mexico Northeast, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New York, Ohio, Oklahoma, Ontario, Pennsylvania, South Dakota, Tennessee, Texas, Wisconsin
Wildlife value
Attracts pollinators
Attracts
Bees; Butterflies
Play value
Attractive Flowers; Easy to Grow; Wildlife Food Source; Wildlife Larval Host
Food & Medicine
Harvest time
Fall
Fruit type
Achene
Landscape Use
Landscape location
Meadow; Naturalized Area; Woodland
Landscape theme
Butterfly Garden; Drought Tolerant Garden; Pollinator Garden; Rock Garden
Design feature
Border
Garden tags
#pollinator plant #dry soils tolerant #blue flowers #bee friendly #showy flowers #butterfly friendly #lavender flowers #butterfly garden #meadow #naturalized area #wildflower #summer flowers #border #rock garden #pollinator garden #drought tolerant #woodland #perennial #fall color #moth friendly
Problems & Resistance
Disease problems
Southern Blight of Herbaceous Ornamentals
Resistant to
Drought; Dry Soil; Erosion

Planted at Hunnicutt

Nobody’s planted this one yet.