Asters Plant Care Guide ~ Varieties
The genus Aster once contained nearly 600 species in Eurasia and North America, but after morphologic and molecular research on the genus during the 1990s, it was decided that the North American species are better treated in a series of other related genera. After this split 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. Aster species are used as food plants by the larvae of a number of Lepidoptera species—see list of Lepidoptera that feed on Aster. 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” (popularly “Michaelmas daisies” because of their typical blooming period) in the horticultural trades. See the List of Aster synonyms for more information.
Some common North American species that have now been moved are:
- Aster breweri (now Eucephalus breweri), Brewer’s aster
- Aster cordifolius (now Symphyotrichum cordifolium), blue wood aster
- Aster dumosus (now Symphyotrichum dumosum), New York aster
- Aster divaricatus (now Eurybia divaricata), white wood aster
- Aster ericoides (now Symphyotrichum ericoides), heath aster
- Aster laevis (now Symphyotrichum laeve), smooth aster
- Aster lateriflorus (now Symphyotrichum lateriflorum), “Lady in Black”, calico aster
- Aster novae-angliae (now Symphyotrichum novae-angliae), New England aster
- Aster novi-belgii (now Symphyotrichum novi-belgii), New York aster
- Aster peirsonii (now Oreostemma peirsonii), Peirson’s aster
- Aster protoflorian (now Symphyotrichum pilosum), frost aster
- Aster scopulorum (now Ionactis alpina), lava aster
- Aster sibiricus (now Eurybia sibirica), Siberian aster
The “China aster” is in the related genus Callistephus.
In the United Kingdom, there are only two native members of the genus: goldilocks, which is very rare, and Aster tripolium, the sea aster. Aster alpinus spp. vierhapperi is the only species native to North America.
Some common species are:
- Aster alpinus, Alpine aster
- Aster amellus, European Michaelmas daisy or Italian aster
- Aster linosyris, goldilocks aster
- Aster scaber
- Aster tataricus, Tatarian aster
- Aster tongolensis
- Aster tripolium, sea aster
Asters are daisy-like perennials with starry-shaped flower heads. They bring delightful color to the garden in late summer and autumn when many of your other summer blooms may be fading.
The plant’s height ranges from 8 inches to 8 feet, depending on the type. You can find an aster for almost any garden and they have many uses, such as in borders, rock gardens, or wildflower gardens. Asters also attract butterflies to your garden!
Aster’s brilliant flowers brighten the fall garden when little else is blooming. Indeed, “aster,” the Latin word for “star,” aptly describes the starry flower heads. Another common name is Michaelmas daisy.
About This Plant
Aster thrives in areas with cool, moist summers. It produces blue, white, or pink flowers in the late summer or fall. Plant height ranges from 8 inches to 8 feet, depending on variety. Tall varieties make good back-of-the-border plants and are also attractive planted in naturalized meadows. Aster is susceptible to powdery mildew and rust diseases, so choose disease-resistant varieties.
Select a site with full sun to light shade and well-drained soil.
Plant in spring, spacing plants 1 to 3 feet apart, depending on the variety. Prepare garden bed by using a garden fork or tiller to loosen the soil to a depth of 12 to 15 inches, then mix in a 2- to 4-inch layer of compost. Dig a hole twice the diameter of the pot the plant is in. Carefully remove the plant from its container and place it in the hole so the top of the root ball is level with the soil surface. Carefully fill in around the root ball and firm the soil gently. Water thoroughly.
Apply a thin layer of compost each spring, followed by a 2-inch layer of mulch to retain moisture and control weeds. Pinch young shoots back to encourage bushiness. Water plants during the summer if rainfall is less than 1 inch per week. Stake tall varieties to keep them upright. After the first killing frost, cut stems back to an inch or two above soil line. Divide plants every three to four years as new growth begins in the spring, lifting plants and dividing them into clumps containing three to five shoots.
How to Grow and Care for Aster Flowers
Growing Asters is easy. Perennial Aster flowers grow well in average soils, but needs full sun. Aster flowers come in blues, purples and a variety of pinks. All Asters are yellow in the center of the flower. They are daisy-like in appearance, even though they are a member of the sunflower family.
Did you know? The yellow center of Asters is actually comprised of many tiny flowerets.
Asters come in a wide variety, with some less than a foot tall, while others are two feet tall or more. Both large and smaller varieties make good cut flowers for vases and arrangements.
Plant Height: up to 24 inches
Flowers Bloom: Summer/Fall
All About Asters