Aster
( ASS - ter )
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At-A-Glance InformationThese perennial flowering plants need full sun and regular water. Their bright blooms attract butterflies. This genus includes over 600 species that range in size, flower color, foliage, and habit. Flowers can come in blue, red, pink, lavender, or purple, and mostly have yellow centers. They bloom in late summer to fall. These plants have a spreading habit, and will grow rapidly via rhizome roots in optimum growing conditions. Plant Asters in containers or potted arrangements or in mixed beds and borders.
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ASter Species and Varietals
The genus Aster is a member of the plant family Asteraceae, and includes somewhere around 170 species. Aster growing zones vary by species; for more information, see the descriptions below. To find your zone, click here: Zone Map.
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Aster alpinus (Alpine Aster, Blue Alpine Daisy) This species is native to European mountain ranges and has pink, purple, or blue flowers that bloom in summertime. These plants prefer a soil pH of between 6.0 and 7.5. |
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Aster amellus (Italian Aster) This species grows best in zones 2-24 and is native to Europe and western Asia. This plant is sturdy, to 2 feet tall and 1.5 feet wide. Flowers are violet with yellow centers, about 2 inches across. Loves alkaline soil. |
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Aster bellidiastrum (False Aster) This species produces white daisy-form flowers and is considered to be a wildflower. |
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Aster dumosus 'Sapphire' Native to the eastern United States, this species grows best in zones 1-24 and is a compact, dense plant. Lilac blooms appear in large numbers in summer and fall. Great for pots. |
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Aster x frikartii Best in zones 2b-24; One of the most widely adapted species of Aster. Forms a loose mound 2 feet tall and wide, with dark green leaves and sprays of lavender to violet-blue single flowers that are excellent for cutting. Blooms from summer to fall in most areas, though will bloom year-round in places with mild climates if flowers are dead-headed regularly. This species attracts bees. Varieties include 'Monch' and 'Wunder con Stafa' ('Wonder of Staffa'). |
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Aster laevis (Smooth Aster) Grows best in zones 1-10 and 14-21, and is native to central and eastern North America. Gets to 3.5 feet tall and 1.5 feet wide, and has smooth foliage that is mildew-resistant and clusters of deep purple-blue flowers. |
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Aster lateriflorus (Symphyotrichum lateriflorum) (Calico Aster) These Asters grow best in zones 1-10 and 14-21 and are native to North America. To 4 feet tall and 1 foot wide. Flowers are purple-pink, and the branching habit is arching and profuse. In early fall, foliage will turn a coppery purple-red color. Needs partial shade. Varieties include 'Lady in Black' and 'Prince', both of which have black-purple stems and leaves and white blooms with red centers. |
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Aster maackii Named for Russian naturalist Richard Maack, this species was first described in 1861 by Eduard August von Regel. These plants produce light purple daisy flowers. |
Aster novae-angliae (New England Aster)
Grows best in zones 1-24 and native to Vermont to Alabama, west to North Dakota, Wyoming and New Mexico. Grows 3-5 feet tall and as wide, and has violet-blue flowers, though varieties of the species has flowers in blue, white, pink, reddish, and deep purple. These plants are tolerant of wet soils, where they will freely reseed, and enjoy full sun to partial shade. Varieties are outlined below.
Grows best in zones 1-24 and native to Vermont to Alabama, west to North Dakota, Wyoming and New Mexico. Grows 3-5 feet tall and as wide, and has violet-blue flowers, though varieties of the species has flowers in blue, white, pink, reddish, and deep purple. These plants are tolerant of wet soils, where they will freely reseed, and enjoy full sun to partial shade. Varieties are outlined below.
'Alma Potschke'
Salmon-colored single-blooms on 2-4 foot tall stems flower from late summer to early fall. |
'Harrington's Pink'
Clear pink single-flowers bloom on 3-4 foot tall stems over the fall season. |
'Purple Dome'
Mildew-resistant variety with bright purple flowers. Compact grower (1.5 feet tall). |
Aster novi belgii (New York Aster, Michaelmas Daisy)
Grows best in zones 1-24 and is a native to eastern North America. Gets to 4 feet tall and 3 feet wide. Blue-violet clusters of flowers contrast with smooth green leaves. Many different varieties are available for purchase, with flower colors that range from white, cream, and blue to lavender, purple, rose and pink. Varietals are outlined below.
Grows best in zones 1-24 and is a native to eastern North America. Gets to 4 feet tall and 3 feet wide. Blue-violet clusters of flowers contrast with smooth green leaves. Many different varieties are available for purchase, with flower colors that range from white, cream, and blue to lavender, purple, rose and pink. Varietals are outlined below.
'Alert'
Has ruby red, semi-double flowers. 1 foot tall, 1.5 feet wide. |
'Jenny'
Double, purple-red flowers. 1 foot tall, 1.5 feet wide. |
'Little Pink Beauty'
Soft pink, semidouble flowers. 1 foot tall, 1.5 feet wide. |
'Prof. Anton Kipppenberg'
Lavender-blue, semidouble flowers. 1 foot tall, 1.5 feet wide. |
'Snowsprite'
White flowers open from pink buds, 1 foot tall, 1.5 feet wide. |
'Audrey'
14 inches tall and a little wider. Lavender-blue flowers. |
'Farmington' ('Baldco')
1.5 feet tall and 2 feet wide, mildew-resistant with lilac flowers. |
'Patricia Ballard'
2.5-3 feet tall and 2 feet wide with dark pink flowers. |
'Apple Blossom'
Pink flowers, grows to about 3 feet tall and wide. |
'Marie Ballard'
Pale blue, double flowers, gets to 3 feet tall. |
'Winston S. Churchill'
Dark red flowers that are semi-double. The plant gets to around 3 feet tall and wide. |
'Climax'
Large sprays of medium-blue blossoms on 6-foot tall stems. |
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Aster tataricus (Tartarian Aster, Tatarinow's Aster) This species is commonly used as an edible plant in Korean cuisine, and produces lavender to bluish flowers. The species forms an erect, tall-growing species that can reach up to 6 feet tall. Flowers are small but abundant, and bloom in fall. Cultivar 'Jindai' is a bit shorter than the straight species, only reaching between 3 and 4 feet tall. Native to Siberia, China, Mongolia, Korea, and Japan. |
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Aster yomena (Kalimeris yomena) (Kalimeris, Japanese Aster) This native of Korea and Japan is used by locals to flavor dishes, and is considered an easy-care plant commonly grown in gardens. Cultivar 'Shogun' has variegated foliage. |
Caring for Aster
Grow Asters in a spot in the garden that receives full sun exposure; between 6 and 8 hours of direct sun each day will result in the best foliage growth and blooms. Asters will adapt to most soil types, but growth is best in fertile soil amended with organic matter. For best growth and bloom, amend soil around the plant site before setting the plant in. Water new plantings regularly as they form a strong root system. Feed with a dressing of organic compost each year in early springtime, adding some to the area before planting and working it into the soil. Taller cultivars can be cut back to encourage bushier growth. Divide yearly in late fall or early spring, tossing the inner growth in the compost bin in favor of the newer, younger outer plants. Less vigorous Asters can be divided once every two years.
Propagation
The most straightforward way to propagate Asters is through division of existing plants. This process will need to be completed every year to every few years (depending on the species and cultivar grown) to ensure the best health for plants. Asters can also be propagated via seed, though this method can result in offspring that do not have the exact same qualities as the parent plant. To propagate your Aster plant, follow the instructions below.
Propagating Aster by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost, and pots (12 inch pots will do, and these are only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring or fall (after the plant has entered dormancy and been cut to the ground, but before it has begun its new spring growth), and needs to be done every four to five years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:
Propagating Aster by Seed
Propagating Aster by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost, and pots (12 inch pots will do, and these are only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring or fall (after the plant has entered dormancy and been cut to the ground, but before it has begun its new spring growth), and needs to be done every four to five years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:
- Gather your materials. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the roots. Once you have worked it up out of the ground, lay it out.
- Start to tease apart the roots with your gloved fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section.
- Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water thoroughly.
- Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout!
Propagating Aster by Seed
- Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
- Harvest your seeds. The seed heads on Aster plants are left behind after flowers have faded. Once they have dried out, you can harvest the seeds. Cut the flowering heads off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
- Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
- Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
Aster seed heads contain many small seeds.
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Aster seeds are very small, and are typically tan to brown in color.
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Problems and Pests
Asters can have issues with the following pests and diseases in the landscape:
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For more information on these pests and diseases, including how to treat them, consult the following pages:
Gallery
A field of massed Goldenrods and Asters.
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In this mixed bed, Asters bring bright color into a fall bed alongside Heuchera, Coleus, Begonia, and variegated Horseradish.
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Videos
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Learn all about these common garden ornamentals.
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How to grow Asters from seed.
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How to care for Asters in the garden.
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Lean why you should choose these flowers for your landscape.
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Resources
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Pages 176 - 177, Aster
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