13 of the Best Companion Plants for Tall Late Season Asters

Late season asters are transitional flowers that bloom between summer and fall, bringing masses of small blossoms and rich texture to end of season gardens.

A garden scene with perennial aster flowers and companions with trees in soft focus in the background. To the center and bottom of the frame is green and white printed text.

In this article, we focus on 13 companion plants that share cultural requirements and stature with late season varieties.

Here’s what’s in store:

Let’s start with some aster basics, and then meet our new friends.

Late season asters are perennials generally suited to gardens in USDA Hardiness Zones 3 to 8.

They thrive in full sun with organically-rich soil that is slightly acidic and drains well. Water needs are moderate, and plants usually exhibit above average drought tolerance once established.

A close up of Stokes' asters growing in the garden in dappled sunshine with trees and shrubs in soft focus in the background.
Stokes’ aster.

There are native and non-native species. Heights vary from one to four feet or more, and it’s not unusual for natives such as the New England aster, Symphyotrichum novae-angliae, to top out at six feet.

Plants have a shrubby, often unruly growth habit, and produce masses of small, daisy-like flowers. They consist of blue, pink, purple, or white rays surrounding a center disk that may be yellow, or yellow aging to reddish purple.

Blooming begins in mid to late summer, and often continues until the first frost.

Some noteworthy species are the calico aster (S. lateriflorum), New York (S. novi-belgii), sky blue (S. oolentangiense), Tatarian (Aster tataricus), and Stokes’ (Stokesia laevis).

Companion plants for asters share similar growing conditions and water needs, and have colors and dimensions that complement one another.

Let’s meet our 13 favorite companions now!

1. Bachelor’s Button

Take it slow with the cool blue tones of perennial bachelor’s button, aka cornflower (Centaurea cyanus), as it sways lazily in the summer sun.

A close up of bright blue bachelor's button flowers growing in the garden, pictured on a soft focus background.

This is a reseeding annual that disperses so many seeds, it comes up reliably year after year, blooming profusely throughout the summer and into the fall.

And while corn farmers may consider it an invasive weed, those with room for meadows full of wildflowers beg to differ.

A close up of white, blue, purple, and pink cornflowers growing in the late summer garden with foliage in soft focus in the background.

Cornflower, Mixed Colors

In addition to my favorite cobalt shade, there’s a lighter “cornflower” blue, as well as pink, purple, red, white, and bicolor combinations.

Mature heights are one to three feet tall.

Find bachelor’s button seeds now from Burpee.

Learn more in our guide to growing bachelor’s buttons.

2. Black-Eyed Susan

Turn the heat up for one last summer blast with mounds of orange-yellow biennial (or short-lived perennial) black-eyed Susan, Rudbeckia hirta.

A flower garden with black-eyed susans and purple perennial asters pictured in bright sunshine, surrounded by foliage.

The bold, black center eyes don’t miss a trick as they watch over the garden en masse.

Bloom time is from midsummer to early fall.

A close up square image of 'Goldilocks' black-eyed susan flowers pictured in bright sunshine in the late summer garden, on a soft focus background.

‘Goldilocks’ Black-Eyed Susan

Heights reach two to three feet at maturity.

Find black-eyed Susan seeds now from Eden Brothers.

See our guide to growing black-eyed Susans to cultivate this classic.

3. Coneflower

Like shuttlecocks at the ready for a sporting round of badminton, perennial coneflower, Echinacea, has drooping petals and protruding flower heads.

A close up of pink echinacea flowers growing in the garden in bright sunshine, pictured on a soft focus background.

Gear up with a palette of colors ranging from the palest pink to the brightest red.

And when the game is over, watch foraging songbirds wing their way to the seed-laden cones for a celebratory feast.

A close up of a purple coneflower in the summer garden, on a soft focus background.

Echinacea ‘Warm Summer’ Mix

Heights range from two to five feet at maturity.

Find coneflower seeds now from Burpee.

Learn more in our guide to growing coneflowers.

4. Goldenrod

The cone-shaped clusters of perennial goldenrod, Solidago speciosa, resonate like emphatic drumbeats among melodious mounds of asters, as they reach toward the late summer sky.

A close up of a butterfly landing on a purple perennial aster growing in the late summer garden, pictured in light sunshine with foliage in soft focus in the background.

They are especially attractive paired with purple asters, accenting the yellow disk centers like perky staccato notes.

A close up of the bright yellow blooms of 'Showy' goldenrod growing in the garden on a soft focus background.

Showy Goldenrod

Mature heights reach two to three feet.

Find goldenrod plants in three-inch containers now from Nature Hills Nursery.

5. Hydrangea

The queen of the cottage garden, flouncy, big-blossomed perennial hydrangea (Hydrangea spp.) is quite at home surrounded by multitudes of aster ladies-in-waiting.

A close up of blue and pink hydrangeas blooming in the summer garden, surrounded by foliage.

With a shared color scheme of blues, pinks, purples, and whites, harmony reigns supreme.

Choose fall-blooming varieties for late season flowers, such as ‘Lavalamp Moonrock’™.

A close up square image of a 'Lavalamp Moonrock' hydrangea flowering in the summer garden, surrounded by foliage.

Hydrangea paniculata ‘Lavalamp Moonrock’™

Heights range from a regal six to 10 feet.

Find plants in four-inch containers now from the Arbor Day Foundation Store.

Our hydrangea growing guide has everything you need to know.

6. Joe Pye Weed

Tiny mauve blossoms cluster in domes atop the towering stems of perennial joe-pye weed, Eutrochium.

A perennial flower border with a variety of different plantings in the summer garden.

Like a canopy of fluffy clouds, they hover in the sultry air, offering a respite from the late season sun for understory plantings.

A close up, square image of joe pye weed growing at the edge of a field with blue sky in the background.

‘Gateway’ Joe-Pye Weed

Heights are between four and seven feet.

Find ‘Gateway’ joe-pye weed plants now from Nature Hills Nursery.

7. Marigold

Like your go-to guy/gal, the marigold, Tagetes spp., is an annual that’s always there when you need it.

A close up of pink perennial asters growing next to marigolds in the late summer garden.

When your asters are getting leggy and leaf-bare toward season’s end, marigolds are right out in front, blocking the view from gawkers just waiting to spread rumors at the popular table.

A close up of a swath of bright orange French marigolds growing in the late summer garden.

French Marigold Tagetes patula

Heights vary from six to 12 inches.

Find marigold seeds now from Eden Brothers.

Cultivation is easy with our marigold growing guide.

8. Montauk Daisy

The cheerful perennial Montauk daisy, Nippoanthemum spp., has bold yellow centers surrounded by crisp white petals, like a starched dress at a summer picnic.

A close up of white montauk daisies with yellow centers growing in the garden, with foliage in soft focus in the background.

A neutral entr’acte, she plays well with all the other guests.

Plants reach 18 to 36 inches tall at maturity.

9. Ornamental Grass

Wispy and windblown, decorative grasses add animal-like movement to gardens in big and small ways.

A flower border with bright pink asters and ornamental grasses in front of windows.

The tallest varieties have commanding forms that dwarf even the tallest asters.

Small ones draw the eye downward to rest for a while on spunky little tufts with wagging blades.

Choose from annual and perennial varieties to add texture to your landscape.

See our guide to landscaping with ornamental grasses for inspiration.

10. Re-Blooming Azalea

If you’re looking for a stalwart sentry for border perimeters that’s a permanent fixture, let azalea apply for the position.

A close up of bright red azaleas blooming in the late summer garden, surrounded by dark green foliage.

A flowering shrub in the Rhododendron genus, it may be deciduous or evergreen.

Some bloom in the spring, and provide a green backdrop to summer plants.

Others, such as re-blooming azalea Encore® cultivars work overtime to give “encore” blooms in the spring, summer, and fall.

A close up of 'Autumn Twist' azaleas in light and dark pink growing in the late summer garden.

‘Autumn Twist’ Encore®

Choose from colors such as fuchsia, ivory, orange-red, pink, red, and bicolor pink/white, and mature heights ranging from two to five feet.

These are best suited to Zones 6 to 9.

Find Encore® azaleas from Nature Hills Nursery.

Consult our guide to growing azaleas for more information.

11. Red Valerian

Cozy like a pair of bedroom slippers, fuzzy red valerian, Centranthus ruber, makes itself right at home in lush meadows and cottage gardens where it naturalizes with ease.

A country cottage garden with red valerian in full bloom and calico asters to the right of the frame, on a blue sky background in UK, one of the few sunny days of the summer season.

Tiny, star-shaped blossoms nestle in voluminous clusters atop stems that reach 18 to 36 inches tall at maturity.

A close up square image of red valerian growing in the garden on a soft focus background.

Red Valerian

Find red valerian now from Nature Hills Nursery.

12. Strawflower

A floral designer’s dream, strawflower, Xerochrysum bracteatum, offers an ample supply of blooms for ready-made everlasting arrangements.

A close up of orange strawflowers growing in the garden in bright sunshine with a wall in soft focus in the background.

The secret is the crisp, straw-like bracts that give the daisy-like blooms a pre-dried quality.

Choose from an array of vivid colors including pink, purple, orange, red, yellow, and white.

A close up of strawflowers 'Swiss Giant' growing in the garden, pictured on a green soft focus background.

Strawflower ‘Swiss Giant’ Mix

This annual (or tender perennial in Zones 8 to 10) blooms from summer to first frost.

Choose from low-profile plants of about 15 inches to tall types measuring over three feet.

Find strawflower seeds now from Eden Brothers.

See our strawflower growing guide for more details.

13. Sunflower

This group of garden buddies wouldn’t be complete without the leader of the pack, the annual sunflower, Helianthus annuus.

A close up of bright yellow sunflowers growing in the garden, with foliage in soft focus in the background.

From high-profile 12-foot giants to one-foot low-riders, you’ll find an iconic entourage that blooms anytime from midsummer to fall.

Rev things up with shades of brown, green, orange, red, white, and yellow.

A close up of sunflowers in a variety of different colors with blue sky in the background. To the bottom right of the frame is a white circular logo with text.

Sunflower All Sorts Mix

At season’s end, the gang’s all here when flocks of larger bird species descend upon the bursting seed heads.

Find seeds now from True Leaf Market.

Our guide to growing sunflowers has everything you need to know.

A Friendly Garden

With similar cultural requirements, including water needs, plants that grow well together are user-friendly choices for the garden.

A close up of purple asters growing in the late summer garden surrounded by other flowering perennials pictured in autumn sunshine.

Now that you’re familiar with 13 plants that play well with late season asters, you’re ready to open your garden planner and head outside.

Select locations with full sun and organically-rich soil that drains well, and remember to allow plenty of room to achieve mature dimensions over time.

And for more information about growing asters in your garden, check out these guides next:

© Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details. Product photos via the Arbor Day Foundation Store, Burpee, Eden Brothers, Nature Hills Nursery, and True Leaf Market. Uncredited photos: Shutterstock.

About Nan Schiller

Nan Schiller is a writer with deep roots in the soil of southeastern Pennsylvania. Her background includes landscape and floral design, a BS in business from Villanova University, and a Certificate of Merit in floral design from Longwood Gardens. An advocate of organic gardening with native plants, she’s always got dirt under her nails and freckles on her nose. With wit and hopefully some wisdom, she shares what she’s learned and is always ready to dig into a new project!

5 4 votes
Article Rating
Subscribe
Notify of
guest
0 Comments
Inline Feedbacks
View all comments