Similar to Chrysanthemums, Aster’s blooming is triggered by the shortened days in the fall. Native to North America, these perennial flowers resemble Daisies.
Asters are an excellent source of late-season color in the garden and also make great cut flowers for arrangements.
Types of Aster Flowers
There are two main types of Asters–The New England Aster and the New York Aster. The New England Aster typically creates a fuller, plump bloom with a thicker stem. This variety also tends to last longer as a cut flower. The New York Aster has smoother leaves in a darker green color and thinner stems.
Barr’s Pink Aster:
A New England Aster, this variety features a rose-colored, semi-double bloom. They grow to a height of approximately 3.5 feet and bloom for a few weeks in mid to late fall.
Hella Lacy Aster:
Another New England Aster with dark-purple blooms. The plant grows up to four feet tall with smaller-than-average flowers. Bloom time is from mid-summer to the first frost.
September Ruby Aster:
This New England Aster blooms a deep red on a bushy plant that grows up to five feet tall. Blooms appear from mid-summer to mid-fall. These beauties will attract butterflies but, thankfully, are rabbit resistant.
Ada Ballard Aster:
A double-bloomed New York Aster, this lavender-blue flower is accented with a bright-yellow center. The plant grows to four feet tall and will produce blooms from late summer to mid-fall.
A single-bloom New York Aster with a lilac-pink flower. This is a dwarf variety that tops out at two feet tall. Enjoy this Aster’s blooms from late summer to mid-fall without worrying about them being eaten as this variety is both deer and rabbit resistant.
Another New York Aster, the Chatterbox features a large, semi-double bloom in pale lilac-pink. Another dwarf type, this Aster will grow to a height of two feet. Bloom time is from late summer to mid-fall.
When to Plant Aster Plants
When you plant your Aster plants will depend on the climate you live in. In Southern climates, plant your Asters in either the spring or fall. Planting at either of these times allows the Aster’s roots to become established before cooler weather sets in, yet does not force the plant to establish itself in the extreme heat of mid-summer. In Northern climates, plant your Asters any time after the risk of frost has passed until early fall to become established before winter.
Selecting and Preparing Your Planting Site
Choose a spot in your garden that receives full to partial sun throughout the day. For those in warmer climates, it is advisable to avoid an area that receives mid-day sun as this will put undue stress on the Asters. Instead, the morning sun or dappled sun is optimal.
Asters prefer soil that is loamy and well-draining. Amend clay-based soils by working in a generous amount of peat moss to lighten up the consistency and improve drainage. For sandy soils, add organic matter, such as compost or aged manure, to slow the drainage factor and increase the soil’s nutrient content.
How to Plant Asters
Begin by loosening the soil in the planting area to a depth of between six and eight inches deep using a shovel or garden fork. Next, dig a hole twice the width of your Asters’ containers and as deep as the container is tall. Remove the Aster from its container and squeeze the root ball to loosen the roots.
Place the plant in the middle of the hole and spread out the roots as much as possible. Backfill around the root ball until the top of the root ball is even with the soil’s surface. Space each plant 12 inches apart for smaller plants and 3 feet apart for mature Asters. Water each plant thoroughly to set in the plant. Lastly, lay a two-inch thick layer of mulch around the base of the plant, leaving a two-inch gap between the stems and mulch. The mulch will help retain moisture and inhibit weed growth.
Companion Plants for Asters
Companion planting has many benefits including staggered bloom time, pest resistance, and design appeal. The following are flowering plants that grow well when planted near Asters.
A perennial flower of similar size to the Aster, Yarrow prefers full sun to part shade. The plant blooms ahead of Asters, typically from June to August and are hardy in USDA zones 3 to 9.
A large, climbing rose makes a beautiful backdrop to groupings of Asters. Roses are perennials and the climbing variety will latch onto a trellis or fence and grow to a height of 20 feet at maturity. Roses prefer full sun and begin blooming in mid-summer, continuing until fall. Roses are hardy in zones 4 to 11.
These sun-loving annuals bloom in bright hues of orange and yellow. Marigolds grow to a height of around four feet and up to two feet wide. The bloom time lasts all season and is plentiful if expired blooms are deadheaded regularly.
Shasta Daisies are another full-sun perennial that grows to three feet tall and two feet wide. As Shasta Daisies are similar in appearance to Asters, they blend well together. Daisies grow best in zones 5 to 9.
These plants can be either a perennial or an annual and are low-growing flowers topping out at nine inches tall and 12 inches wide. Tuck these delicate flowers into bare spots around your Asters in either full sun or partial shade. Alyssums will grow as perennials in zones 5 to 9 but will do well as annuals in colder climates as well.
Caring for Asters
Keep new Aster plants moist, but not soggy, from planting until blooming is finished. Aim for consistently moist soil but avoid getting water on the foliage as it leads to mildew and fungal issues for the leaves.
Asters are moderate feeders who bloom and grow best when given a balanced fertilizer during the growing season. Give your Aster plants their first feeding in the spring and follow up with a second application in August.
As blooms die throughout the growing season, pinch off the expired blooms to redirect the plant’s energy toward new growth and blooms. Asters make excellent cut flowers in arrangements and cutting blooms regularly also encourages more bloom production.
Overwintering Your Asters
When blooming is finished, and there’s two to three weeks left before the first frost, give your Aster plants one last deep watering of between 1 to 2 inches. Once the frost kills off the plant’s foliage, cut the entire plant back to soil level and cover the area with mulch to provide protection during the winter.
Growing Asters FAQ
There are over 600 different Aster species that are grouped into two main types–New England and New York Asters.
While Asters resemble Daisies in appearance, they are actually a member of the Sunflower family. The Aster’s yellow center, like the Sunflower, is made up of a network of micro flowers.
Asters are often given in remembrance of a loved one who has passed. In addition, the Aster’s meaning is also associated with lasting love, wisdom and faith.
The Aster is the official birth flower for September.
No, the Aster is not toxic and is, in fact, considered an edible flower that works well in salads or to make tea.