Asters are beautiful late summer and fall blooming perennials that add pops of color to the garden when many other flowers have faded. With their daisy-like flowers ranging from purple, pink, red, blue, and white, asters provide a feast for pollinators like bees and butterflies.
But what do asters look like before those flowers open up? Identifying asters in their early growth stages can be tricky since the plants look quite different before they bloom This guide will walk you through exactly what to look for so you can recognize asters at every stage of growth
The Basics on Asters
Before diving into identifying asters early on, let’s quickly review some background on these popular perennials
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There are over 600 species of asters The two main types planted in home gardens are New England asters (Symphyotrichum novae-angliae) and New York asters (Symphyotrichum novi-belgii)
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Asters are hardy perennials that bloom in late summer through fall. They grow 1-6 feet tall depending on variety.
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They thrive in full sun to partial shade and prefer moist, well-drained soil. Hot afternoon sun should be avoided in warmer climates.
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Deer tend to leave asters alone thanks to their unpleasant taste.
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Asters spread slowly by rhizomes and self-seeding. Established plants can be divided every 2-3 years.
What Asters Look Like as Young Plants
Asters started from seed indoors or purchased as young plants look fairly nondescript. Here’s what to look for:
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** Seedlings** – The first true leaves will be oval or rounded with slightly toothed edges. Stems are green and hairless.
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Young plants – Leaves remain oval as the plant grows, turning more lance or spoon-shaped. They are light to medium green and alternately arranged on green stems. Leaf undersides may have fine hairs.
Young aster plants don’t give many clues to their identity. You’ll need to wait until they mature more to determine the species. Label unknown plants for later identification.
Identifying Mature Asters Before Bloom
As asters grow, their features become more distinctive. Here are tips for identifying asters by sight before they bloom:
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Plant height – Note if the plants are short (under 2 feet), medium (2-4 feet) or tall (over 4 feet). This helps narrow down the species.
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Leaf shape and texture – Are the leaves broad oval, spoon-shaped, or slender? Do they have hairs on the undersides or smooth surfaces? Coarse or fine texture?
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Stem color and texture – Stems may be green, reddish, or dark brown. They may be smooth or hairy.
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Branching pattern – Is the plant upright, columnar, bushy, or spreading in form based on the stem branching?
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Flower buds – Scan plants for developing flower buds which are round swellings along stems. Buds help confirm you have an aster.
Some key features to distinguish asters by species:
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New England asters – Tall, up to 6 feet. Thick hairy stems and lance-shaped, hairy leaves with rough texture.
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New York asters – Range in height from 1-4 feet. Thinner green or reddish stems with lance-shaped, hairless leaves of medium texture.
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Heath asters – Compact at 1-2 feet tall. Very slender leaves and wiry stems. Profuse tiny white buds pre-bloom.
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Aromatic asters – Up to 4 feet tall with multiple branched stems. Oval leaves are slightly hairy with distinct aroma when crushed.
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Smooth asters – Medium height with slender reddish stems and hairless, lance-shaped leaves of medium green.
Once plants start forming flower buds, it’s easier to recognize them as asters. Refer to the photos above to identify the aster species in your garden based on key characteristics before the flowers open.
Caring for Asters Before Bloom
Proper care of asters earlier in the season ensures good flowering later on. Here are some tips:
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Pinch back stems by 1/3 in early summer to encourage bushy, compact growth.
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Apply a balanced organic fertilizer or compost in spring.
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Water during dry spells to keep soil evenly moist.
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Monitor for pests like leaf-eating insects.
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Stake tall varieties to prevent flopping later when in bloom.
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Divide mature plants every 2-3 years in early spring.
Enjoying the Aster Bloom Season
The fun part of growing asters is finally seeing those flowers open up on mature plants. Here’s an overview of enjoying asters in bloom:
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Bloom times – Asters bloom from late summer through the fall, providing color as other flowers fade. The bloom period can last up to 6 weeks.
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Flower forms – Flowers have classic daisy shapes with yellow central discs surrounded by ray petals. They may be single, semi-double, or fully double blooms.
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Colors – Asters come in beautiful hues of purple, violet, pink, magenta, red, blue and white. Some varieties have color-changing blooms.
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Uses – Cut asters for bouquets, leave them for pollinators, or enjoy as striking mass plantings in borders and wildflower gardens.
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Deadheading – Snip off spent flowers to encourage more blooming into the fall.
Knowing exactly what asters should look like before they bloom helps you properly identify, grow, and enjoy these late season perennial beauties. Pay attention to their key characteristics at each stage of growth for gardening success. Then sit back and wait for that gorgeous burst of fall flowers!
You Can Get Big Performance With Little Effort
If you want more blooms, pinch your asters. Trimming some stems back in early summer will provide you with a longer bloom period in fall.
“Pinching” (pruning or using hedge shears) aster stems back by about one-third in early June in the North and late June in the South will extend the season even more. Asters look great on their own in the summer and fall. This makes it take a few weeks longer to bloom, so if you pinch some and leave some, the fall bloom will last much longer. If you pinch after June, though, you’ll cut off flower buds that are just starting to form, so the plant will flower less.
When you pinch plants early, they get bushier and more compact, so they don’t need to be staked as much. Otherwise, asters that are 4 feet tall or more usually need to be staked to keep them from flopping over. If you don’t have time to worry about staking or pinching, choose shorter selections.
Under ideal conditions, asters may self-seed after bloom. If you don’t want seedlings to grow everywhere the next year, just cut off the flowers as soon as they bloom.
Other types of asters
Like the perennial heath, the heath aster grows to be 3 to 4 feet tall and has tiny, narrow leaves. In late summer and early fall, it blooms with hundreds of small white daisies, though some cultivars may bloom a little later.
Calico aster is like heath aster, but it’s about a foot or two shorter and has flowers that grow along one side of the stems in the fall, which is how it got its name.
The aromatic aster grows to be about 2 to 4 feet tall and has many stems that branch out. Each stem has a few large flowers that are about an inch across. It is one of the latest to bloom in fall. The leaves are about an inch long and narrow, but not as much as the last two types. Its foliage releases a slight aroma when brushed against. If you see a blue aster with smooth stems and blue-green leaves, it is likely smooth aster. The native aster grows to be about 3 to 4 feet tall. The stems are often reddish, and the leaves are egg- to lance-shaped. Flowers appear in early to midfall.
This plant is a bit taller, at 4 to 6 feet. It is often called heart-leaf aster because of the shape of its hairy leaves when they are fully grown. The flowers dot along the smooth, thin, dark stems and are less than an inch wide. They bloom over several weeks in late summer into fall.
Learning About Asters
FAQ
What month do asters bloom?
What does aster look like in spring?
What triggers asters to bloom?
Do asters come back every year?
When do asters flower?
Seedlings can be planted into the ground throughout spring to flower in late summer and fall. Potted asters from your local nursery will normally be available closer to mid-summer when the plants are almost ready to flower. Space the plants around two feet apart, with some leeway depending on the size of the chosen variety.
How tall do asters grow?
Learn all about planting, growing, and caring for asters. Cold-hardy perennials with daisy-like flowers, aster flowers are the pollinator stars of the garden from late summer through fall. Growing 1 to 6 feet tall, depending on variety, these upright flowering plants bear cheerful star-shaped flower heads ranging from purple to white to blue.
What are asters & what do they look like?
Asters are a large group of plants, consisting of many different species, each one offering something different in height, colour and design potential. There are many cultivars available to provide you with good displays of late summer and autumn colour, with daisy-type flowers in shades of white, pink, purple, blue and red.
What is an aster flower?
Aster flowers are part of the Asteraceae family. They are known for being frost-hardy perennials with daisy-like flowers surrounding a yellow center. The name aster comes from an ancient Greek word meaning “star.” I love this plant’s vibrant colors, which range from deep purple to white and blue, depending on its variety.