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Symphyotrichum chilense (Aster chilensis) - Pacific aster

Symphyotrichum chilense (Aster chilensis) - Pacific aster

Symphyotrichum chilense

Pacific aster

This West Coast native perennial had its name changed in 2013 from Aster chilensis to the much harder to pronounce Symphyotrichum chilense.  It's an adaptable, fast-growing evergreen perennial that "grows to between 1 and 3' tall and spreads by rhizomes (underground stems).  The daisy-like flowers are about 1½" in diameter and are lavender with yellow centers.

Natural habitat and range
In the wild, Pacific aster is found from Santa Barbara County north to British Columbia.  It grows in meadows, on open slopes, in clearings, salt marshes and on coastal bluffs in many plant communities below 4,500 feet.

Growth habit and flowers
Pacific aster is a fast-growing, evergreen perennial.  Its growth habit can be variable; sometimes it tends to sprawl, sometimes it sends out very upright branched stems that can grow to 3' tall.  Plants spread rapidly by purplish-colored rhizomes (underground stems) to form a dense mat of foliage.

The leaves are lanceolate (lance-shaped) and about 2" long.  In the wild, they vary in color from dark glossy green to dull olive.  The plants we grow at Gold Rush have upright stems, dark glossy green leaves and blueish-lavender flowers.

Daisy-like flowers, about 1-1½" in diameter, bloom in summer on short branched stems along the main stem and also at the tip of the main stem.  Flowers can be blue, lavender or white with a yellow center.  The yellow center is actually a cluster of small disk-like flowers that's surrounded by colored petals.

Exposure
Pacific aster is tolerant of a range of exposures from full sun to light shade.  Plants tend to be slightly sturdier and produce more flowers in sunnier locations. 

Soil
Pacific aster's tolerant of a wide range of soils from moist to dry and from heavy clay to sand.

Watering
Once established, plants will survive with no summer water.  In years with particularly dry winters, they will benefit from an occasional deep watering from mid-summer through fall.  In moist soils, plants will always appear more lush and will spread much more quickly.

Pests and Diseases
Pacific aster isn't often affected by any pests or diseases.  In warm humid summers there may be an outbreak of powdery mildew (a fungal disease) on the leaves.  However, this isn't anything to be majorly concerned about.  You can cut off the affected stems and dispose of them in your green waste can if the outbreak is particularly bad or unsightly. 

Aphids (small fat-bodied insects with piercing mouthparts that suck the sap out of plants) sometimes congregate in clusters on soft, sappy young growth.  If the infestation's bad, you can prune off the affected stems or you could spray the bugs with horticultural soap. 

Suggested uses
Pacific aster is a good addition to meadows and mixed borders.  Its vigorous growth and ability to form dense mats of foliage helps prevent surface erosion on slopes.  It makes a good cut flower and is a valuable source of pollen and nectar for a wide range of bees, butterflies and other insects.

Wildlife
Pacific aster's a good source of both pollen and nectar for a wide variety of insects including native bees, predatory and parasitoid beneficial insects and butterflies.  It's also a host plant for the larval (caterpillar) stages of the Northern checkerspot, field crescent and pearl crescent butterflies. 

 



Pacific aster Growing and Maintenance Tips

Cut Pacific aster back to the ground after it's finished blooming.  If you're able to water it through the summer, you may be rewarded with a second flush of flowers.


Height:

2-3 ft

Spread:

2-3 ft

Spacing:

2-3 ft

Plants that work well with Symphyotrichum chilense

Coyote mint Coyote mint (Monardella villosa ssp. villosa)
California goldenrod California goldenrod (Solidago velutina ssp. californica)
California fescue California fescue (Festuca californica)
Deer grass Deer grass (Muhlenbergia rigens)
Twin Peaks Dwarf coyote brush Twin Peaks Dwarf coyote brush (Baccharis pilularis 'Twin Peaks II')
Valley Violet ceanothus Valley Violet ceanothus (Ceanothus maritimus 'Valley Violet')
Sticky monkey flower Sticky monkey flower (Mimulus aurantiacus)
Allen Chickering's sage Allen Chickering's sage (Salvia 'Allen Chickering')