Aster Flowers: Your Guide To Who’s Who In The Family

One of the many things I love about late summer are the throngs of colorful, star-shaped flowers that pop up all over the landscape. Most of us are familiar with the yellow ones (sunflowers). But did you know that the same family also produces flowers in purple, red, pink and white? These plants are all part of the Aster family, Asteraceae, the largest and most diverse group in the plant kingdom.

THE ASTER FAMILY STORY

Indeed, the Aster family (also known as Compositae and daisy) is exceedingly large. There are estimated to be over 27,000 known species. They may differ in color, shape and form, but most share two key characteristics. Most plants are composed of two types of flowers, disc and ray.

Gaillardia is a member of the aster family.

Yes, they may look like one flower, but asters are actually composed of many, all fused onto a single flower head. Disc flowers are located in the center and ray flowers are found at the perimeter. The ray flowers are what we commonly refer to as petals.

Zoom in on the photo and you’ll see that the disk is not flat, but domed. And it’s made up of hundreds of tiny flowers.

Leucanthemum (daisy) displaying both tubular and ray florets.

That said, within the family, there are also deviations. Some species consist of only disc flowers while others have only ray. 

The flower head of Globe Thistle contains no petal flowers.

Scientists believe that the aster flower head, which also contains seeds and nutrients, helps the plants store energy during periods of drought. It also may contribute to their longevity. In my own experience, I’ve noticed that once established, my Aster family members like coneflower, daisy and blanket flower require very little water. And certainly the many roadside sunflowers, daisies and asters are living proof of these flowers’ remarkable survival ability.

UNEXPECTED FAMILY MEMBERS

Of course every family has its outliers, and the Aster family has a few. These include the food crops lettuce, chicory and globe artichokes. Notice the two types of flowers, both tubular and ray, on the mountain lettuce bloom below.

Mountain lettuce

TAKE THE ASTER FAMILY QUIZ!

Despite all these variations, I still find the yellow asters the hardest to identify. At first glance, many of the flowers look alike. But on closer inspection, their flowers are all slightly different.

Below are some well-known Aster family members that bloom in late summer and early fall. Can you identify them? (For answers, please see below.)

Answers: (from top) Coreopsis grandiflora, Golden Marguerite, Rudbeckia (Black-Eyed Susan), Helianthus tuberosis (Jerusalem artichoke), Helenium autumnale (Common Sneezeweed), Helianthus annum (Sunflower), Heliopsis helianthoides (Smooth Oxeye), Gaillardia (Indian Blanket Flower), Arnica montana

GREAT ASTERS FOR GARDENS

Ready to add some of these beautiful flowers to your garden? (or just be able to identify some more members of the family). Following is a list of well-known aster species and their value in the garden.

ORNAMENTALS

echinacea purpurea

Echinacea purpurea

These popular flowers can be found in gardens all over the world. Popular members include: New England Aster, Echinacea, Rudbeckia, Cosmos, Daisy, Fleabane, Dahlia, Coreopsis, Liatris, Blanket Flower, Fleabane, Zinnia, Chrysanthemum, Oxeye daisy and Yarrow.

HERBAL TEAS, MEDICINE AND FOOD

arnica flower

Arnica flower

Aster flowers, leaves and roots have been used for millennia to treat various ailments and diseases. These species include Calendula (Pot marigold), Chamomile, Echinacea, Arnica, Endive, Lettuce and Artemisia.

GREAT NECTOR PRODUCERS

fleabane

Fleabane

Since they bloom late in the summer and into the fall, asters are a great source of nectar and pollen for pollinators. Some of the best producers are Helianthus annus (Sunflower), Goldenrod, New England Aster and Fleabane.

INSECTICIDAL PROPERTIES

French marigold

French marigold, Tagetes patula

Some asters are great at repelling insects. The most well-known among them are marigolds. French marigolds are known to repel whiteflies while Mexican marigolds are said to not only stave off insects but rabbits as well. Other effective ‘insecticidal’ species include Tanacetum, False Fleabane and Chrysanthemum.

WEEDS

ragweed

Ragweed is a member of the aster family.

Weeds are members, too. Dandelion, Ragwort, Ragweed and Sneezeweed are all part of the Aster family.

Want to know more? For a detailed list of Asteraceae, its genera and where the family fits in the plant kingdom, click here for the USDA Natural Resources Conversation Service.

Looking for garden inspiration? To see photos of my designs, including plant lists, check out my Instagram at carole.herebydesign. I post seasonally from spring through fall. 

 

Flowering Kale: The Coolest Cool-Season Ornamental

Long before it became a trending food, flowering kale was a garden star, delivering a pop of color to fall’s graying landscape. The plant is not only prized for its striking foliage but it’s also one of just a few species that thrives in cold weather. In fact, flowering kale likes cold temperatures so much that it often stays attractive well into winter. I can’t think of a better choice for fall gardens and containers. Continue reading

Top Annuals for the All-Season Cutting Garden

Annuals for the cutting garden/Photo: Julie Hove Anderson Photography

As a landscape designer, I’m well versed in perennials and the kind of annuals you buy from a nursery. But when it comes to growing annuals from seeds, my experience lies mainly with zinnias. So recently, I was delighted to attend a webinar hosted by ButterBee Farm owner Laura Beth Resnick on the top annuals she grows for her cutting gardens. Continue reading

Identify Plants In A Snap With These 6 Top Apps

 What's That Flower app

Now that we’re all spending more time at home, it can’t hurt to know what’s blooming. And finding the answer is easier than ever with one the many plant identification apps available. But which ones work best and provide the fastest, most reliable data? To find out, I decided to do a side-by-side comparison. Continue reading

The Secret To Creating Fabulous Fall Containers

Cool-season flowering plants

In my view, autumn doesn’t have to spell the end of the show in the garden. Fall containers offer countless ways to still enjoy seasonal splashes of color. Moreover, these mini gardens no longer have to be all about flowering kale or mums. With a little ingenuity, you can create autumn planters every bit as beautiful as their lush summer cousins. Continue reading

Lespedeza: The Best Fall-Flowering Shrub You’ve Never Heard Of

lespedeza thunbergii

Lespedeza. Judging by the sound of it, you’d think it was an island off the coast of Italy. The plant that bears its name certainly looks Mediterranean. Yet, I had never heard of this magnificent, fall-blooming shrub until a client of mine showed me a pair in her garden. Here’s why I’ve been a fan ever since. Continue reading

How To Pronounce Botanical Names (Hint: It Doesn’t Matter)

Just the other day, I was working with a bunch of Master Gardeners preparing a garden for the county fair when one of them noticed a bare space. Sure enough, in one of the central beds, a group of plants had recently given up the ghost on a prominent corner. In no time, we all agreed that a lacy evergreen would be the perfect replacement. And that’s when I suggested chamaecyparis. Continue reading

How To Deadhead Popular Types Of Flowers

Most flowering plants need lots of sun to keep on blooming. Still, over time, the blooms often start to diminish. That’s where deadheading can make all the difference. Not only does it keep plants looking neat, but it also promotes new growth and re-flowering. And, there’s nothing quite like getting a plant to re-bloom that otherwise looks done for the season. 

WHAT IS DEADHEADING?

Simply put, deadheading is the practice of removing spent (dead) flower heads from a plant. 

Dried poppy seed heads

All plants follow the same life cycle; that is, they grow, produce flowers, set seeds and die. No sooner do the blooms fade, and a plant turns its energy to setting seed. That said, by removing spent blooms, you can delay production of seeds. This in turn redirects energy to flowering. The result is a healthier, more vigorous plant that blooms for a longer period of time.

HOW TO DEADHEAD

Regular deadheading benefits all blooming plants. However, the world of flowers is diverse and many species require their own specific methods. Here are tips on how to deadhead six key types of flowering plants:

Clusters of flowers with leaves on their stems

Purple garden phlox

These types of flowers include tall, leggy plants like phlox, yarrow, daisies. To keep your plant looking neat, remove the spent flowers just before they die back completely.

A good rule of thumb is to reach into the plant and prune the spent flowers back to the first or second set of leaves. This not only helps hide the cut, but it also encourages the plant to bush out as it produces new blooms. I vary the lengths at which I cut to keep the plant shapely.

Flowers with no leaves on their stems

Long-stemmed orange daylily

Flowers like daylilies and hostas have no leaves on their stems. Cut the entire stalk back to the base of the plant once it has finished flowering.

Salvias

Multiple flower spikes of salvia make pruning tedious

Once the initial flush of flower spikes start to brown, salvias look like they’re done for the season. With proper deadheading, however, you can encourage them to keep on blooming.

What may at first glance look like a single flower stalk is actually three flower stalks growing together – a central stem surrounded by two, smaller ones on either side. As soon as the central stalk starts to wither, remove it. This will encourage the side shoots to grow.  Then, once the side shoots lose their color, cut them off too.

Deadheading salvias in this way can encourage the plant to re-bloom at least twice and sometimes three times during the season, especially if you feed it mid way through the summer. Try one of these stunners for great summer color: Salvia patens Cambridge Bluebright red Salvia Jezebel, or the traditional purple/blue favorite Salvia x sylvestris May Night.

Bushy plants with small flowers

Coreopsis verticillata

Bushy perennials like coreopsis can be encouraged to produce a second round of blooms way past their typical flowering time.

However, it can be tedious deadheading so many tiny flowers. Instead, I grab big chunks of spent blooms in one hand and shear them back with a pair of long-blade shears in the other. This not only encourages the plant to re-bloom a week or so later, it keeps thinks looking tidy. Try soft yellow Coreopsis Moonbeam for reliable blooms all summer.

Roses

With roses, the number to know is ‘5’

Most of us know that roses need to be deadheaded to flourish. Remove withered blooms by pruning back to above a five-leaflet leaf, cutting on an angle.

Annuals

Geraniums need consistent deadheading to look their best

All annuals need to be deadheaded regularly to thrive (with the possible exception of begonias, in which case you should prune the leaves.) Popular annuals like geraniums and petunias must be constantly snipped, pinched or cut back to keep flowers looking neat and to encourage blooming. For a more in-depth tutorial on how to prune these annuals, click here for How To Keep Your Potted Plants In Shape All Summer

Self-seeders

Butterfly weed is a prolific self-seeder

Some flowers, like columbine, echinacea and butterfly weed are prolific self-seeders. If you’re looking to produce lots of new baby plants, leave the seed heads on and they’ll quickly spread around your garden.

DEADHEADING WON’T DAMAGE THE PLANT

It’s rare to damage a plant by cutting it. Use common sense while removing spent flowers, taking care to hide your cuts under existing foliage. Remember to sterilize your pruners regularly to prevent spreading disease between plants. You’ll reap the rewards of a new flush of blooms!

Looking for garden design ideas? I post photos of my landscape projects on Instagram

 

Dreamy Dahlias: How To Identify Your Perfect Type

Minus some advance planning, fall usually spells the end of the garden. But if planted in spring, dahlias will flower non-stop through autumn. Lately, I’ve been waking up to crisp mornings only to discover more and more blooms. Who knew October could bring so many fresh flowers?

DAHLIAS BRING OUT THE CHILD

For some, dahlias may not be all that big a deal. But for me, the first time I saw the majestic, 10-foot flowers left an indelible memory. It was the 1960s, and I was a kid growing up in Delaware. Smack dab in the middle of suburbia, on the corner of two heavily-traveled streets, there was a small working farm. In the summer it produced fruits and vegetables. But in September, it grew dahlias.

And these weren’t your everyday dahlias, mind you. Many were the gigantic, dinner plate size; the kind that drives a kid mad with desire to jump out of the car just to be among them. Standing as tall as adults, they gently swayed in the breeze, solemnly saluting as we drove by. 

Craning my neck out the window, I’d watch until they disappeared, slowly dissolving into a sea of rainbow colors.

And thus began my love affair with these beautiful flowers.

SO MANY TYPES, SO LITTLE TIME

Dahlias are classified as tender perennials, meaning they may be annual or perennial, depending on the climate. They typically start blooming in August with other late-summer flowers. But the best thing about them is that they don’t stop blooming until the first frost, or roughly right around Thanksgiving.

And in spite of their reputation for towering stems and gigantic blooms, the plants come in all shapes and sizes. Dahlia types can range in height from the very tall specimens of my childhood to just under one foot. Planting the tubers is easy. Just dig a hole 6 to 8 inches deep and drop them in with the ‘eyes’ facing up. Three or more tubers per hole usually gives the most colorful effect.

FLOWERS AS BIG AS A FOOT

Still, it goes without saying that the most notable feature of all dahlias are the flowers. These can range in diameter from 2 inches to almost one foot. And among these, there are specific dahlia types, each with its own specifications. For example, there are species with single, double and semi-double petals. And there are unusual shapes like spherical or cactus. There are also types that resemble flowers such as anemones, peonies or orchids.

waterlily dahlia 'Pam Hayden'

Waterlily dahlia ‘Pam Howden’

Notwithstanding the variety, one thing all dahlia types have in common is their dazzling color. These flowers come in a seemingly infinite array, including all shades of pink, red, scarlet, orange, purple and yellow. Moreover, the flower petals often come painted with strips or tips of another color. (There are also creamy ones as well as many brilliant white species.) 

In sum, with so many options to choose from, how do you decide? One way is to familiarize yourself with the most common types. You may be surprised to find that some don’t look like the ‘typical’ dahlia. 

THE TEN MOST COMMON DAHLIA TYPES

Single-flowered dahlias feature a single row of flat or slightly cupped ray petals surrounding a central disc.

single-flowered dahlia

Single-flowered dahlia

Semi-double dahlias have two or more rows of petals surrounding a central disc.

semi-double dahlias

Semi-double dahlias

Mignon dahlias are similar to single dahlias except their petal florets are rounded and their disc flowers have no more than two rows.

mignon dahlia

Mignon dahlia with burgundy/black foliage

Anemone dahlias have an inner disc made up of tubular shaped florets and an outer ring of one or more rows of flat ray petals.

anemone dahlia 'Polka'

Anemone dahlia ‘Polka’

Orchid dahlias have open centers with just one row of ray florets surrounding a disc. The petals are often overlapping and curled for most of their length.

orchid dahlia

Orchid dahlia

Collarette dahlias have one row of flat petals surrounding a disc as well as an inner wreath of shorter petals called the ‘collar’.

collarette dahlia

Collarette dahlia ‘Mary Eveline’ plum red petals with white ‘collar’

Ball and Pompon dahlias are shaped like balls and feature double flowers with rounded or blunt tipped florets. Pompons are slightly smaller than ball dahlias.

pompom dahlias

Orange ball dahlias – notice the slightly flattened shape

pompom dahlia

The perfectly round pompon dahlia ‘Franz Kafka’

Decorative dahlias are doubles that feature flat, oval petals with tips on the end. Formal varieties have regular, evenly placed petals, while informal varieties tend to be arranged in a more haphazard way. Both varieties grow to over 40 inches.

decorative dahlia 'Lisa Dark Pink'

Decorative dahlia ‘Lisa Dark Pink’

Cactus and semi-cactus dahlias have narrow pointed petals that roll back on themselves, giving them a spiky look. Cactus types are rolled for their full length, while semi cactus types include a mix of flat and rolled petals. Both reach an average height of around 40 inches.

cactus dahlia

Orange cactus dahlia

semi-cactus dahlia 'Aloha'

Semi-cactus dahlia ‘Aloha’

There are many other varieties, including peony, waterlily and stellar, not to mention the celebrated ‘Dinner Plate’ which falls under numerous categories. The Miscellaneous Dahlias category alone includes hundreds of varieties.

Ready to add dahlias to your garden? Every year, among the ten top things I want to achieve or change in my garden, I resolve to plant more. Here’s how.

WHEN TO PLANT DAHLIAS

Dahlias are sold as tubers and need to be planted after the ground has warmed up and there’s no danger of frost. I usually plant mine in the late spring just around the time my tulips have faded. Plant the tubers in well drained soil in full sun for best results. You can also pot them up indoors a couple weeks beforehand to give them a head start.

dahlia tubers

Dahlia tubers need to winter indoors in a cool, but not cold, space

Dahlias are considered tender in my neck of the woods (Zone 6), but hardy outdoors in zones 8 to 10. That means that once they’re done flowering in the fall (or right after the first frost), I must dig them up. I then label them and store them in a dry spot in the basement. Click here for the USDA Plant Hardiness Map to see where you fit. 

To see photos of my garden designs, including plant lists, check out my Instagram at carole.herebydesign. I post seasonally from spring through fall.