How To Grow and Care For Hardy, Aromatic Hardy Asters

Symphyotrichum oblongifolium (sim-fy-oh-TRY-kum ob-long-ee-FOH-lee-um) is a wild, native member of the Asteraceae family of plants. 

This perennial wildflower is native to North America and grows in various natural settings throughout the United States and northeastern Mexico.

flowering asters growingPin

You may also hear this plant referred to as:

  • Eastern Aromatic Aster
  • Aromatic Hardy Aster
  • Aromatic Aster
  • Native Aster
  • Wild Aster

The plant’s genus name, Symphyotrichum, is derived from the Greek words symph (coming together) and trich (hair). This is probably a reference to the plants’ slightly fluffy seeds.

The specific epithet, oblongifolium, is Greek for “oblong leaves.”

Hardy Asters Care

Size and Growth

Wild Aster has a compact, upright, mounding growth habit. Individual plants may attain a height and spread of 1′ to 3′ feet.

Its dark green foliage and stems are aromatic when crushed. The leaves are between 1″ and 3″ inches long. 

You’ll find mature longer leaves at the base of the stem, medium leaves in the middle, and shorter, new leaves at the top. 

Flowering and Fragrance

The plants’ pretty, showy, purplish-pink, daisy-like blooms with yellow centers are on display from late summer until early winter. However, the bloom time may vary depending on the variety of aster.

This slightly fragrant native wildflower is especially beneficial to a wide variety of specialized native bees. The blooms are also quite long-lasting when used as cut flowers.

Light and Temperature

Aromatic Aster flowers like full sun but will grow in partial shade. This cheery native wildflower is winter hardy in USDA hardiness zones 3a to 8b.

Related: Growing Aster Novae-Angliae

Watering and Feeding

Aromatic Hardy Aster does well when treated as the wildflower that it is. For the most part, it will thrive on natural rainfall. 

In times of extreme drought, occasional deep watering is appreciated, as they have drought tolerance once established.

Water at ground level, but avoid overhead watering. They don’t like to sit in soggy soil, so ensure there is excellent drainage.

Moreover, it’s best to maintain an inch of water per week, especially for first-year plants in the absence of rain.

A three-inch layer of organic compost will help retain moisture while providing the plants with more than enough nourishment. Take care not to let the mulch come in contact with plants’ stems, which may lead to fungal problems.

Soil and Transplanting

Aster flowers will do well in almost any rich soil. However, they thrive in fertile, well-drained, moist soil. Moreover, they prefer slightly acidic soil.

They are also not opposed to poor, rocky, sandy soil, but poorly draining soil with high clay content will cause problems with root rot, powdery mildew, and other fungal disorders.

If planting young plants or divisions, be sure to place the crown of the plant at the soil level. Newly planted Wild Aster should be deeply watered, and the soil kept slightly moist until the plants become well established.

Adding organic mulch is also recommended to supply nutrients and retain moisture. 

Grooming and Maintenance

As the season progresses, plants may tend to topple over. You may want to stake them. Alternatively, you may prune them mid-season.

Late in the autumn or early in the winter, prune the plants to the base, leaving the rosette of leaves at ground level. You can also pinch back the hardy aster’s growing tips between late spring and early summer to encourage more blooms and bushier growth.

If plants become overcrowded, divide them. 

Moreover, it’s important to stake or cage tall varieties of asters to keep them from falling over.

How To Propagate Hardy Asters

Hardy Aster seeds (achenes) have little tufts of hair and are easily blown about by the wind and will set roots in such diverse settings as dry woodlands, prairies, rocky outcrops, dry open ground, disturbed soil, slopes, loose shale, and limestone.

Mature plants also spread through underground runners.

If planting Aromatic Aster from seed, sow it right on the surface of the prepared soil and press the seeds into the soil. They need exposure to light and air to germinate.

If you encourage them to grow in a wild-scaped setting, you can lay the pruned branches with spent aster flowers on the surface of the soil where you want them to grow. You may wish to mow them using a mulching mower, but don’t cover them deeply.

If you wish to reduce an existing stand of Wild Aster, you can divide it and transplant the extras in a new setting.

Moreover, you can also propagate hardy asters via division. Just separate the pieces with your knife from the mother plant along the edge of the root ball.

Hardy Asters Main Pest or Diseases

As long as Hardy Asters are not overwatered or overcrowded and are getting plenty of sun and good air circulation, pest and disease problems are fairly non-existent.

However, too much moisture, too little drainage, or too little light will lead to fungal diseases like root rot and powdery mildew complications.

Examples of other diseases that can affect your aster varieties include:

Other common insect pests that can attack hardy asters include aphids and lace bugs.

In addition, Wild Aster is not attractive to deer and rabbits.

Is the plant considered toxic or poisonous to people, kids, and pets?

Native Asters are non-toxic.

Is the plant considered invasive?

These native plants are not aggressive and are not considered invasive.

Suggested Hardy Asters Uses

These enthusiastic wildflowers do well in mass plantings in various settings, providing pops of color in late summer and fall.

It’s also great to plant asters close to spring flowers in your garden, so their beautiful purple flowers can take over when the spring flowers fade.

They are also fairly easy to control for use with bordering walkways or providing a backdrop to a coastal, wildlife, butterfly, or pollinator garden.

In addition, perennial asters also make a good container plant in autumn gardens.

Moreover, the aster plants provide good habitats for small garden mammals, reptiles, amphibians, and other beneficial pollinators, making them a good choice for a wildlife habitat restoration project.

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