Dahlia Flower Types: A Guide to Groups and Classification

Dahlias are beloved by gardeners and florists for their large array of glorious colors and delightful flowers that range from miniature pompoms to giant dinnerplates!

Flowering from midsummer until the arrival of frost, they add fresh beauty to beds, borders, containers, and window boxes through the dog days of summer – just when other plants start to wear out from summer’s heat.

But with over 57,000 registered cultivars worldwide, choosing a selection for your garden can be a challenge.

A close up vertical image of different dahlia types in a variety of different colors and forms. To the center and bottom of the frame is green and white printed text.

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The American Dahlia Society (ADS)categorizes dahlias into three groups on the basis of color, form (or flower type), and size.

In our guide to growing dahlias, we cover how to cultivate these beauties. In this guide, we’ll take a look at the different classifications to help you choose the type that’s right for your garden.

Here’s what I’ll cover:

Color

The ADS Color group lists 15 distinct shades or color combinations.

A close up horizontal image of different types of dahlia flowers growing in the garden pictured in bright sunshine.
  • Bicolor (two distinct and clearly separated colors)
  • Bronze
  • Dark blend (blends of dark hues)
  • Dark pink
  • Dark red
  • Flame
  • Lavender
  • Light blend (blends of lighter tints and pastels)
  • Orange
  • Pink
  • Purple and Black
  • Red
  • Variegated (two or more colors with dots, splashes, or streaks)
  • White
  • Yellow

With every color available except true blue, you’re sure to find just the right shade for your garden palette.

Form

There are also multiple flower types in the Form group, with different petal structures and bloom shapes.

1. Anemone

Anemone (AE) types are distinguished by at least one row of evenly spaced, flat ray petals surrounding a vivid, and often contrasting, pincushion center made of long, tubular florets.

A close up horizontal image of an orange anemone flowered dahlia pictured on a soft focus background.

They may also be bicolored, as in the case of ‘Polka Dot’ which features cream colored petals edged in dark pink surrounding a bright yellow center.

A close up square image of an anemone-flowered dahlia growing in the garden pictured on a soft focus background.

‘Polka Dot’

Blooms are four to six inches wide, and plants grow to a mature height of three to four feet.

You can find bags of two, four, or eight tubers available at Eden Brothers.

2. Ball and Miniature Ball

Ball (BA) types are fully double flowers with a slightly flattened globe shape featuring furled, involute (incurved) petals in a gorgeous, spiral arrangement. Petal tips can be blunt, flat, or indented. 

Miniature Ball (MB) types have identical flower forms but in smaller sizes.

A close up horizontal image of a Ball type dahlia growing in the garden pictured on a soft focus background.

‘Ivanetti’ features deep purple, three- to four-inch blooms atop three- to four-foot stems.

A close up square image of a dark red ball dahlia 'Ivanetti' growing in the garden pictured on a soft focus background.

‘Ivanetti’

The globe-shaped flowers make a dramatic impact in the garden and in cut flower arrangements.

You can find bags of two, four, or eight tubers available at Eden Brothers.

3. Cactus, Incurved Cactus, and Semi Cactus

Cactus (C) types have long, pointed ray florets with petal edges that are involute (IC), revolute (edges rolled back), or straight (SC), radiating out from an open center in a somewhat spiky look.

A close up horizontal image of a bright pink Cactus dahlia flower pictured on a soft focus background.

‘Bora Bora’ is an eye-catching cultivar with bright red to pink flamboyant petals that fade to yellow towards the center.

A close up square image of a Cactus-flowering 'Bora Bora' growing in the garden with foliage in the background.

‘Bora Bora’

Adding texture, color, and interest to beds and borders, plants top out at two to three feet tall with large, six- to eight-inch blooms.

Find bags of two, four, or eight tubers available at Eden Brothers.

4. Collarette

Collarette (CO) flowers have a flat, open face with a single outer row of regularly spaced ray florets, an inner collar of shorter petals (petaloids), and a fringed or tight center disk.

The inner collar and center disk are often contrasting.

A close up horizontal image of a deep red and white bicolored Collarette dahlia with a bright yellow center pictured on a soft focus background.

‘Night Butterfly’ is a superb example of a Collarette dahlia, featuring deep red outer petals, with ruffled white and pink inner petals surrounding a yellow center.

A close up square image of a Colarette dahlia flower 'Night Butterfly' pictured on a soft focus background.

‘Night Butterfly’

Two- to four-inch flowers bloom on stems that grow up to three feet tall.

Eden Brothers carries bags of two, four, or eight tubers.

5. Decorative, Formal and Informal

Decorative cultivars are double petaled and open centered, with flat florets that may have a roll at the edges or tips.

A close up horizontal image of white decorative dahlias growing in the garden pictured on a soft focus background.

Formal Decoratives (FD) have evenly spaced petals and a symmetrical flowerhead while informal Decoratives (ID) have twisted or wavy petals in a more irregular arrangement.

With 10-inch dinnerplate flowers in light pink fading to a creamy-white center, ‘Gitts Perfection’ is an Informal Decorative type.

A close up square image of a Decorative 'Gitts Perfection' dahlia flower growing in the garden.

‘Gitts Perfection’

Plants grow three to four feet tall, and may require staking.

Find ‘Gitts Perfection’ tubers available at Eden Brothers.

6. Laciniated

Laciniated (LC) types have uniformly arranged florets radiating from a disk or open center with involute or revolute edges.

A close up vertical image of a bright yellow Lacinated dahlia flower pictured on a soft focus background.

A lengthwise split at the tips of the petals gives a fringed or “pinked” appearance like that of a carnation.

7. Mignon Single

Mignon Single (MS) is an open faced flower with a single row of uniform, slightly overlapping ray florets, in a flat plane surrounding a center disk that can be tightly furled or unfurled into a pincushion.

A close up vertical image of bright red Mignon Single petaled dahlia flowers growing in the garden.

The delicate four-inch flowers are stunning when mass planted in beds and borders, and are available in a variety of colors. Compact plants top out at one- to two-feet tall.

A close up square image of red, pink, white, and yellow Mignon dahlia flowers pictured in bright sunshine.

Mixed Mignon

You can find seeds for D. variabilis in a mixed packet of pinks, reds, yellows, and whites available at Eden Brothers.

8. Novelty, Open and Fully Double 

Novelty flowers have characteristics that fall outside of the other classifications.

A close up horizontal image of Novelty dahlia flowers in pink and white, growing in the garden pictured on a dark background.

Novelty Open (NO) varieties have a disc center. Fully Double (NX) types have an open center surrounded by double petals.

9. Orchid

Orchid (O) types feature open flowers with a single row of uniform ray florets surrounding a tight disk center.

A close up horizontal image of a deep red Orchid dahlia with a bright yellow center pictured on a soft focus background.

The florets are involute for at least two thirds of their length, giving a narrow, rolled effect.

‘Honka Pink’ is a lightly fragrant Orchid type, with deep pink petals fading to soft pink and white towards their bases, surrounding a bright yellow center.

A close up square image of an orchid flowering dahlia flower 'Honka Pink' pictured on a soft focus background.

‘Honka Pink’

Four-inch-wide flowers are light and stand erect atop three-foot stems.

Find ‘Honka Pink’ tubers available at Eden Brothers.

10. Orchette

Orchette (OT) types are intricate blooms that combine the involute petal characteristics of the Orchid dahlia with an inner fringe of short petals (petaloids) surrounding a center disk typical of the Collarette form.

A close up horizontal image of a bee feeding from the pollen of a pink Orchette dahlia flower pictured on a soft focus background.

The petaloids may be flat or slightly curved towards the center of the bloom.

11. Peony

Peony (PE) types feature an open flower with two or more rows of flat or slightly cupped ray florets surrounding a center disk of open anthers on short filaments.

A close up horizontal image of a bright orange Peony-flowered dahlia flower pictured in light sunshine on a soft focus background.

‘Fascination,’ a winner of the RHS Award of Garden Merit in 1994, is a compact Peony type featuring bright pink petals that surround a dark center.

A close up square image of a pink peony-flowered dahlia 'Fascination' flower pictured on a soft focus background.

‘Fascination’

Flowers are five to six inches across on three- to four-feet-tall sturdy stems.

Find bags of two, four, or eight tubers available at Eden Brothers.

12. Pompom

Pompom (aka pompon) types (P) feature an open-centered, fully double flower in a rounded globe shape with rolled, involute florets that are blunt or round tipped.

Flowers are beautifully symmetrical with an appealing geometry.

A close up horizontal image of deep purple pompon dahlia flowers growing in the garden pictured on a soft focus background.

‘Burlesca’ is a coral-pink cultivar with dainty four-inch flowers that look perfectly symmetrical.

A close up square image of a pompon dahlia flower 'Burlesca' pictured on a soft focus background.

‘Burlesca’

Flower stalks can be up to three feet tall and may require staking.

You can find ‘Burlesca’ tubers available at Eden Brothers.

13. Single

Single (S), is an open faced flower with a single row of regular, overlapping ray florets in a flat plane surrounding a center disk.

A close up horizontal image of a yellow single petaled dahlia flower with dark green foliage in the background.

The petals are flat or slightly cupped with blunt or pointed tips, and the center disk opens to reveal frilly anthers.

14. Stellar

Stellar (ST) types are fully double flowers with long and pointed cupped florets that recurve back towards the stem, giving the appearance of a shooting star.

A close up horizontal image of dark red Stellar dahlia flowers growing in the garden pictured on a soft focus background.

Like the Ball types, there is no center disc.

15. Waterlily

Waterlily (WL) has fully double, symmetrical blooms with slightly cupped florets that open from a domed center to a saucer-shaped face.

A close up horizontal image of a bright red waterlily dahlia flowers growing in the garden pictured on a soft focus background.

Petals are broader and sparser than the Stellar types.

Size

The third group is Size, classified according to letter values.

  • AA – Giant flowers, measuring over 10 inches in diameter (also known as Dinnerplate)
  • A – Large flowers of 8 to 10 inches (also known as Dinnerplate)
  • B – Medium flowers of 6 to 8 inches 
  • BB – Small flowers that measure 4 to 6 inches
  • M – Miniature flowers up to 4 inches
  • BA – Ball types measuring over 3.5 inches 
  • MB – Miniature Balls of 2 to 3.5 inches 
  • P – Pompoms up to 2 inches 
  • MS – Mignon Single, up to 2 inches

Like the Color and Form groups, the large selection of sizes offers a good variety of flowers suitable for multiple environments.

From small patio or courtyard spaces to large garden beds, there’s ample selection for any setting.

Best for Your Garden

Now that you’re familiar with the different classifications and have learned how to identify dahlia flower types, have you decided which will be best for your garden? 

A close up horizontal image of a number of different types of dahlia flowers.

From anemone to waterlily forms, you’re sure to find a few new favorites to brighten up your late season landscape – tell us about your selection in the comments section below!

And for more know-how on growing dahlias, be sure to add these articles to your reading list:

About Lorna Kring

A writer, artist, and entrepreneur, Lorna is also a long-time gardener who got hooked on organic and natural gardening methods at an early age. These days, her vegetable garden is smaller to make room for decorative landscapes filled with color, fragrance, art, and hidden treasures. Cultivating and designing the ideal garden spot is one of her favorite activities – especially for gathering with family and friends for good times and good food (straight from the garden, of course)!

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