Aster
Aster species. ASTERACEAE (COMPOSITAE).
Planting and Growing Aster
You’ll find everything you need to know to plant and grow aster in the accompanying table’s tabs:
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- Flowers, foliage, and root structure of aster
- Plant hardiness and growing conditions for aster
- Season of bloom and planting time for aster
- When, how deep, and where to plant aster
- How to plant aster
- Watering, fertilizing, care and pests or diseases of aster
- Landscape and container uses of aster
- Comments about aster and its features
Growing Aster
Over 600 species of bushy, upright, sometimes shrublike, deciduous, mostly perennial herbs, to 4–60 in. (10–150 cm) tall and wide, with tall flower stalks. Hairy, deep green, lance-shaped leaves, 3–5 in. (75–125 mm) long.
See also China Aster, Callistephus chinensis, a closely related annual plant. Stokes’ Aster, Stokesia laevis, has a somewhat similar appearance but is a member of a different plant family.
Planting and Care Guide
Blooms
Showy, blue, pink, purple, red, white, daisylike flowers, to 2–1/2–in. (63–mm) wide, in late summer–autumn.
Best Climates
Hardy. Zones 2–9.
Soil Type and Fertility
oist, well-drained, sandy soil. Fertility: Rich–average. 6.0–7.0 pH.
Where and How to Plant
Spring in full to filtered sun, 3–4 ft. (90–120 cm) apart, when frost hazard has passed and soil is workable.
Proper Care
Easy. Keep evenly moist. Fertilize monthly during growth. Deadhead spent flowers to prolong bloom. Divide when crowded. Propagate by cuttings, division.
About This Plant
Good choice for accents, backgrounds, containers, massed plantings in cottage, formal, natural, wildlife gardens and water feature margins. Good for cutting. Attracts birds, butterflies. Very invasive. Aphid and mildew, aster yellows susceptible.
Common Species of Aster
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- Alpine aster, Aster alpinus
- Big-leaved aster, Aster macrophyllus
- Blue wood aster, Aster cordifolius
- Bushy aster, Aster dumosus
- Great aster, Aster grandiflorus
- Heath aster, Aster ericoides
- Italian aster, Aster amellus
- Late purple aster, Aster patens
- Michael aster, Aster bellidiastrum
- Michaelmas daisy, Aster novi-belgii
- New England aster, Aster novae-angliae
- Seaside aster, Aster spectabilis
- Smooth aster, Aster laevis
- Tatarian aster, Aster tataricus
- White wood aster, Aster divaricatus
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About Aster
Nearly 625 species of rarely annual or biennial, but mostly perennial herbs are included in the Aster genus. All have composite, daisylike flowers with showy rays surrounding a disk made up of many tiny flowers. Most are rhizomatous or fibrous-rooted, and they are native to every continent except Antarctica.
Cultivated species range in height from 4–6 in. (10–15 cm) tall for ground covers to more than 6 ft. (1.8 m) for tall plants with shrublike habits. While the solitary or clustered flowers vary in size, most are 1–2-1/2-in. (25–63-mm) wide. Flower colors include blue, pink, purple, red, and white.
Most asters are sturdy, fast-growing plants. While generally pest and disease resistant, they’re susceptible to powdery mildew. Use them in wildlife gardens where their bright blooms and abundant seed will attract both birds and butterflies. Many cultivars are self-seeding or will multiply freely.
Asters are the right choice for landscape gardens, whether for a colorful accent, a background for a mixed-perennial border, or a massed planting. They perform well in containers, planters, and pots in small-space gardens such as decks, balconies, and patios.
Asters flower in summer to autumn in a long-lasting display that makes them right for cutting and arranging. Choose from the popular species listed.
Planting and Caring for Aster
Plant asters in early spring in full to filtered sun. They are tolerant of sun and heat once they become established, as long as they receive regular waterings to keep their soil evenly moist. They perform best in loose, well-drained soil and loam containing equal parts of sand and humus.
Asters are the right choice for landscape gardens, whether for a colorful accent, a background for a mixed-perennial border, or a massed planting. They perform well in containers, planters, and pots in small-space gardens such as decks, balconies, and patios.
For best flowering, feed them with nitrogen liquid fertilizer every month as they sprout and grow. Reduce your fertilizer applications after flower buds form to avoid too much foliage at the expense of flowers. As flowers fade, pinch them off to encourage new buds to form.
Perennial asters will thrive in the garden—some species and hybrids are invasive if planted adjacent to turf or flower beds. The central plants in a group will fade over time as they lose vigor and their offspring compete for nutrients. Renew your plantings in late autumn or early spring by dividing the roots, discarding the central plants, and replanting the young offshoots in the bed’s center.
Asters are the right choice for heritage gardens, whether formal or informal. Their reputation for reliable color is well deserved. For generations, asters have been a featured part of many generations of flower gardens.