Aster (genus)

Plant Characteristics

Lifespan:	⌛	perennial

Cultivation

USDA Zones:		1 to 11

Scientific Names

Asteraceae >

Aster >

Read about Aster (genus) in the Standard Cyclopedia of Horticulture

Aster (a star). Including Diplopappus. Compositae. Aster. Starwort. Michaelmas Daisy. A large temperate-zone genus of attractive but botanically- confused, mostly perennial leafy herbs, particularly abundant in North America; very useful for border planting. The genus is characterized- by numerous flattish rays (white, blue, red, or purple), slender subulate or lanceolate style appendages, compressed several- nerved achenes, and an involucre with unequal bracts in few or several rows, the pappus simple, soft, and abundant (Fig. 417); leafy stemmed, mostly blooming in the autumn: Lvs. always alternate. It differs from Erigeron in having 2 to several rows of involucrate bracts; in Erigeron there is only 1 series of bracts. Some of the species are annual, but those in cult, are perennial (or rarely biennial). Calimeris and Linosyris, which have yellow fls., a color unknown in aster, are kept distinct in this book. In North America, where the asters are such abundant plants in the autumn flora, the species are not much known as cultivated plants, most of the specimens seen in gardens being the wild species transplanted. In Europe, however, there are numbers of named garden kinds, some of them derived from American species that have been long cultivated there. A. novi-belgii has been particularly productive of garden forms. Many of the garden forms are undoubtedly confused hybrids. The Michaelmas daisies are mostly from this species and perhaps also from A. novae-angliae. Many of the Latin- form garden names are very difficult to place. The native asters are amongst the very best plants for borders and roadsides. They should be better known. A. acuminatus grows well in shade in ordinary soil, not necessarily moist; increases in vigor under cultivation. A. cordifolius prefers open or partial shade; improves much under cultivation with good soil. A. corymbosus prefers at least partial shade, and will grow even in very deep shade; seeds very freely; does well on dry ledges and in small crevices in rock; very tenacious of life. A. dumosus prefers full sunlight and dry situation. A. ericoides wants full sunlight and dry situation; will grow in very poor or shallow soil, but does best where roots can penetrate deep. A. hevis grows in either full sunlight or partial shade and good soil. A. novas- anglix will not endure much shade; prefers moist soil, but grows well in ordinary garden situations. Fall- sown seedlings of A. novae-angliae var. roseus come practically true to varietal name, though varying in shade of color, and these seedlings bloom later than older plants and at a height of 18 inches, making the plant of value as a late bedding plant treated as an annual. A. novi-belgii prefers moist soil; will not endure heavy shade. A. paniculatus prefers moist soil, but will do well in rather dry situations; will endure more shade than either of the two above species. A. patens wants open or half-shaded places, and good soil; one of the weaker species, often proving shortlived. A. puniceus will not endure shade; prefers moist places, but will grow in good soil not over-moist; in dry situations it loses its vigor; spreads rapidly in favored locations. A. spectabilis prefers open or partly shaded places; one of the weaker species in wild state; rather short-lived. A. undulatus wants open or half shade; late-flowering, handsome plant, forming large clumps when allowed to develop. (F. W. Barclay.) The garden or modified asters undoubtedly deserve more attention in American collections. The beautiful low-growing, vernal alpine asters are little known at present, but are valuable for rock-garden and for bordering purposes. The earliest asters to flower are the Alpine varieties. These are well adapted for floral mass effects, and transplant well, even in an advanced state. There are many garden varieties of asters, among which are Schoene von Ronsdorf, Ultramarin, Beauty of Colwall, Beaute Parfaite, Rosalind and Boule de Neige. Alpine asters can be easily raised from seed sown in spring. Seedlings do not flower until the second year. In the garden they require a light rich soil, open exposure and moderate amount of moisture. Plants retain their foliage over winter and for this reason need a more careful covering than the tall-growing classes require. Garden varieties of the latter, as a rule, dp better in low and rather moist locations. Here a minimum of care is sufficient. To bring out their full beauty. however, it is necessary to plant them in well-prepared richly manured ground and properly to cultivate, stake and irrigate them. Stock of named varieties must be purchased as plants. Propagation can be effected by division of old clumps, or, if larger quantities are desired, by cuttings. If distinctness of variety and color is no object, seeding may be employed; sow early in spring, thinly in rows; transplant seedlings in August or early in September and await their coming into flower the following season. The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.

Aster (syn. Diplopappus Cass.) is a genus of flowering plants in the family Asteraceae. There are roughly 180 species within the genus, all but one being confined to Eurasia. The name Aster comes from the Ancient Greek word ἀστήρ (astér), meaning "star", referring to the shape of the flower head. Many species and a variety of hybrids and varieties are popular as garden plants because of their attractive and colourful flowers. Asters can grow in all hardiness zones.

The genus Aster is now generally restricted to the Old World species, with Aster amellus being the type species of the genus, as well as of the family Asteraceae. The New World species have now been reclassified in the genera Almutaster, Canadanthus, Doellingeria, Eucephalus, Eurybia, Ionactis, Oligoneuron, Oreostemma, Sericocarpus and Symphyotrichum, though all are treated within the tribe Astereae. Regardless of the taxonomic change, all are still widely referred to as "asters" in the horticultural trades. See the List of Aster synonyms for more information.

Cultivation

Aster calendar?
January:
February:	sow
March:	sow
April:	divide
May:	transplant
June:
July:	flowering
August:	flowering
September:	flowering
October:	divide
November:
December:
Notes:

Easy to grow?

Propagation

• Division - Divide clumps every two years as growth starts in the spring. Select strong crowns from around the outside of the existing clump and discard the weak central section.
• Seed - Sow either in spring or autumn in a cold frame.
• Cuttings - Take 2 inch long softwood cuttings in spring, use a sandy compost mix, and place in a cold frame to root.

Pests and diseases

The two main diseases which infect asters are rust and powdery mildew, both of which can be avoided by:

• making sure plants are well-spaced to allow for good air circulation; and
• watering plants at the roots so as to avoid the foliage becoming excessively wet.

Rust can be easily identified by the orange pustules which form on the underside of the leaves.

Powdery Mildew appears like a white sooty residue on the upper-side of the leaves, quickly causing defoliation.

Species

• Aster alpinus (Alpine Aster)
• Aster amellus (European Michaelmas Daisy or Italian Aster)
• Aster linosyris (Goldilocks Aster)
• Aster pringlei
• Aster scaber
• Aster sibiricus
• Aster subulatus (Hairless Fleabane)
• Aster tataricus (Tatarian Aster)
• Aster tongolensis
• Aster tripolium (Sea Aster)

Gallery

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  New York Aster (Symphyotrichum novi-belgii)

• 

  Aster tongolensis

• 

  Heath aster (Aster ericoides)

• 2003 0928 133251AA.JPG

  Michaelmas Daisy

References

• w:Aster (genus). Some of the material on this page may be from Wikipedia, under the Creative Commons license.
• Aster (genus) QR Code (Size 50, 100, 200, 500)
• Flora: The Gardener's Bible, by Sean Hogan. Global Book Publishing, 2003. ISBN 0881926248
• American Horticultural Society: A-Z Encyclopedia of Garden Plants, by Christopher Brickell, Judith D. Zuk. 1996. ISBN 0789419432
• Sunset National Garden Book. Sunset Books, Inc., 1997. ISBN 0376038608