Are Asters Considered Annual, Biennial, or Perennial Plants?

Are you thinking about planting asters this season, but aren't sure if they'll come back year after year? Asters are a popular wildflower, and are quite beautiful when in bloom. In this article, we examine if asters are considered annual, biennial, or perennial plants!

Written by Jason Wilson Last updated: October 10, 2023 | 5 min read

Single perennial aster flower up close with lavender bloom

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Asters are delightful, small flowers in the shape of a star. They are often seen alongside mums and pansies as part of a fall-themed bouquet. Since asters are some of the last flowers to bloom in the year, they are especially lovely and colorful in a garden.

Perennial plants are grown to come back year after year. Annual plants last only one growing season. Both have many benefits and some cons to take note of. So, are asters considered annuals or perennials?

Most of the time, asters are sold as annuals in nurseries and at plant shops. Is this true, or can asters live longer than one season? To answer this question, we’re going to dive into the life cycle of asters and whether or not they are annual flowers.

The Short Answer

Asters are considered easy to grow perennial plants. They will return year after year in regions where the temperatures are mild. Hardiness zones in which the temperatures are more extreme, whether cold or scorching hot, are best for growing asters as annuals.

The Long Answer

Purple Perennial Blooms in a Sunny Garden with sunlight glinting off the beautiful display of lavender colored blooms. There are over thirty flowers, each is a bright purple color, and each bloom has a yellow center stamen. — There are over 600 varieties of these star-shaped blooms.

Asters are perennial, fall-blooming flowers. They can come back year after year for several years. These small, star-shaped flowers come in more than 600 different varieties. Their cheery blooms brighten up any garden in the late summer and early autumn months. However, to keep them truly perennial, a gardener must properly care for asters.

Perennial flowers will come back for at least three years. If asters are properly cared for during the dry summer months and in the winter, asters will last beyond a single season. Asters typically have a four-to-five-year lifespan, but they can live for much longer.

Annual vs. Perennial

Purple blooming flower growing in garden. There are many bright lavender flowers with yellow stamens and silvery light green foliage at the base of each plant. — Annual flowers and perennial flowers have different life cycles after they are planted.

Flowers have different life cycles that depend on the hardiness of the flower and the harshness of the weather. While certain flowers thrive better within different hardiness zones, others have a shorter life span and do not live more than a year or two.

There are three classifications of life length: annual, biennial, and perennial. Annual flowers live for one season, dying off each winter and spreading seeds for next year’s crop. These seeds then provide the next generation of flowers to spread the plant.

Biennial flowers live for two years – they can survive one winter but are generally weak in their second year of life. After one winter, the second winter wipes them out, and it’s time to start fresh.

Any flower that lives longer than two seasons is considered a perennial flower. It doesn’t matter whether it lives for 3 years or 30 years, these flowers can survive two winters and come back.

It’s essential to note that it’s not about how cold the winters get. Certain tropical flowers can live for years in a tropical climate but die in a single frost and are still considered a perennial. The classification depends on how long the flower will survive before fading naturally and spreading its seeds.

Aster Hardiness Zones

Pink blooming flowers in the morning sun. The flowers have pink petals with a bright yellow center stamen. There is green foliage growing at the base of the plant. — Although sold as annuals, these flowers are primarily perennials.

You may have heard that asters are annuals. Well, the answer to this is a little more complicated than just yes, or no. While asters are primarily perennials, a few factors will prevent them from surviving winter and cause them to be annual flowers. It also depends on the hardiness of the specific type of aster.

Many garden centers and greenhouses sell asters as annual flowers. These pre-arranged pots or displays create a lovely fall decoration for a front porch or patio. However, the asters you buy at a nursery sale are probably not annual plants. If you take care of them, you can keep them for several years.

Asters thrive in hardiness zones 3-8 as perennials. If you live outside of these zones to the north, you can probably plant asters as annuals. However, the cold winters will kill them off each year. Hotter climates should keep asters in pots indoors, so they don’t dry out.

There are only a few annual or biennial aster variations. These include some modified or crossbred species and can be found in specialty flower markets. However, asters that are sold as annuals are perennial flowers generally. They simply need the proper care and maintenance.

Aster Life Cycle

Blooming purple flowers in the garden. There are three blooms, and a number of different smaller flower buds that are ready to bloom in the garden. — Plant asters in the early spring to enjoy blooms in the late summer to fall.

Asters live for 4-5 years, depending on the stability of the ecosystem around them and the harshness of the winters. They thrive in the medium zones, 3-8, which have regular winters and long summers.

Gardeners suggest planting asters in the early spring to give the seeds the longest time to grow before heat kicks in. Seeds should be planted earlier than potted plants to give them a chance to mature and blossom throughout the summer.

In the spring and summer, aster plants grow and develop buds. They won’t bloom quite yet, but the plants will add a shade of green to the garden. If you plan the rest of your garden well, you can have blooming flowers at every time of the year.

Asters bloom in late summer and early fall, making them one of the last flowers of the season. They bloom around the same time as mums, another autumn classic. The color of the aster depends entirely on the variation. Since there are hundreds of different types of asters, you can get any color you desire!

Dormancy and Overwintering

Purple flower has bloomed in the garden and has snow on the petals. The middle of the flower has yellow stamens, but the flower itself appears to have gone dormant. — Asters have a dormancy period during the wintertime.

Asters go through a dormancy period during the winter months. As long as the aster variety you’ve planted is hardy to your hardiness zone, they will drop their blooms in wintertime, and will come back again in the spring.

No special care is required for overwintering if planted in their native hardiness zones. With that said, if you are going to experience an unusual drop in temperatures for any reason, the best thing you can do to keep them alive is cover them with burlap or some other winter covering during the temperature drop.

You can also prepare their garden beds by covering them with an organic mulch. Follow these winter care tips to help prepare for more extreme weather than they may be used to, which will help them survive through more severe weather.

Growing as Perennials

Purple flowers growing in a wildflower garden. There are hundreds of small blooms with yellow stamens growing together in a shrub form. — When grown in their native hardiness zones, most aster varieties can be grown perennially.

In their native hardiness zones, most asters can be grown as perennial plants. This means they will come back every season with the same beautiful blooms they have the first year you’ve planted them. They are also native wildflowers in many regions across the United States.

Asters are one of the easiest flowers to grow as perennials as little care is needed both during the winter and during the summer. In fact, there are more pros than cons to growing them perennially.

Pros of Growing as Perennials

Return each season.
Requires very little care.
Save money not buying new plants.
Can always replace later.
Native to the United States.

Cons of Growing as Perennials

Sensitive to extreme cold.
Certain varieties are quick spreaders.

Growing as Annuals

Flowers grown in a pot as annual plants. The plants have different bloom colors, including white, pink, and lavender purple. They are all growing out of a black plastic pot at a nursery with other plants in the background behind them. — Asters are commonly grown as annual flowers, regardless of the hardiness zone.

Like many garden flowers, asters are commonly planted as annuals. Even though their seeds are in wildflower mixes available at most garden stores and nurseries, many gardeners buy asters in pots or containers and treat them as annual flowers each season.

The good news is, even if you buy them as an annual plant, if the Aster is grown in its native habitat, they can be placed in the grown and treated as a perennial going forward.

The only true disadvantage to treating Asters as annuals is the cost associated with purchasing new plants each season.

Pros of Growing as Annuals

Replace flowers each season.
Experiment with different varieties.
Beautiful early-spring colors.
Can purchase new plant starts each season.

Cons of Growing as Annuals

Less cost-effective.
New plant starts may not thrive.

Final Thoughts

Asters are perennial plants that are often sold as annuals. Many gardeners prefer to treat them as annuals because it’s easier to purchase them, let them flower, and replace them at the beginning of each growing season.

However, they can last several years as perennials in a well-kept garden and continue to bring life and color to the season’s last weeks. No matter what type of aster you plant in your garden, you will love these joyful little flowers.