Types of dahlias: 25+ category classes (plus example cultivars)

Dahlias are one of the most beloved types of flowers, covering an incredible breadth of sizes, colors, and forms. There are over 10,000 different varieties that all fit into 29 different types of dahlias.

There are currently 25+ types of dahlias available. The American Dahlia Society (ADS) categorizes dahlia varieties into different types based on the size and form of the flower. Each dahlia cultivar is then further classified by color and given a 4-digit ADS classification code number that describes its size, form, and color. This classification system is used by flower farmers, gardeners, and plant nurseries.

Read on to learn all about the many different types of dahlias!

1. Formal Decorative dahlias (FD, 0)

Formal Decorative Dahlias are medium-large uniform dahlias with layers of short broad petals curving geometrically around the center of the flower. The many layers of petals give them the appearance of a large fluffy pom-pom. These symmetrical beauties have cupped flat petals with rounded tips that wind in smooth curves with a uniform appearance.

• Lilac Time Dahlia
• Kelvin Floodlight Dahlia
• Boom Boom White Dahlia
• Boom Boom Red Dahlia

Formal Decorative Dahlias are perfect for large formal floral arrangements. Formal Decorative Dahlias are given the classification code “FD” and the classification number “0” (which is preceded by a size classification number – see the section at bottom of this article entitled “Dahlia Size Categories & Classification Codes”).

Further Reading: ADS Dahlia Classification and Number Guide

Source: American Dahlia Society

2. Informal Decorative dahlias (ID, 1)

Informal Decorative Dahlias are large irregular dahlias with long, wavy petals. Many of the largest and most popular dahlias are categorized as Informal Decorative-type flowers. The generous petals of these flowers can get so long that they almost appear twisted or curled towards the pointed tips. Here are some gorgeous examples of varieties of Informal Decorative-type dahlias:

• Café au Lait Dahlia
• Spartacus Dahlia
• Break Out Dahlia
• Spoiled Rotten Dahlia

Informal Decorative Dahlias are excellent flowers for large, romantic flower arrangements. Informal Decorative Dahlias are given the classification code “ID” and the classification number “1” (preceded by a size classification number #1-6).

3. Semi-Cactus dahlias (SC, 2)

The Semi-Cactus Dahlia is a larger type category in which the petals are somewhat curled over, resulting in skinny rolled petals. This is another very popular type of dahlia with both home gardeners and farmer florists. The petals are not as skinny as the fully-cactus types listed further on but are still much skinnier than the large decorative types. Here are some popular Semi-Cactus type dahlia varieties:

• American Dream Dahlia
• Mingus Randy Dahlia
• Ludwig Helfert Dahlia
• Bon Bini Karma Dahlia

Semi-Cactus Dahlias are wonderful in bouquets and in a wide variety of floral arrangements. Semi-Cactus Dahlias are given the classification code “SC” and the classification number “2” (preceded by a size classification number #1-6).

4. Cactus dahlias (C, 3)

Cactus Dahlias are a specialty-type category in which flowers have long, skinny petals creating a dahlia flower with a spiky look. Flowers in this unique type tend to be large and are available in many different shades. The tubular petals are mainly straight and uniform in length. This type is sometimes referred to by florists as “Straight Cactus Dahlias”. Here are some popular Cactus-type dahlias:

• Bora Bora Dahlia
• Apricot Star Dahlia
• Alauna Pochette Surprise Dahlia

Cactus Dahlias are striking feature flowers for floral arrangements. Cactus Dahlias are given the classification code “C” and the classification number “3” (preceded by a size classification number #1-6).

5. Incurved Cactus dahlias (IC, 4)

Incurved Cactus Dahlias are a particularly unique type of dahlias with curled cactus-type petals that curve upwards toward the center of the flower. The upwards curl of the petals gives these flowers a fun-loving cheerful appearance.

• Alfred Grille Dahlia
• Clearview Citron Dahlia
• Camano Sitka Dahlia
• Bright Star Dahlia

Incurved Cactus Dahlias are perfect for whimsical arrangements and for children’s gardens. Incurved Cactus Dahlias are given the classification code “IC” and the classification number “4” (preceded by a size classification number #1-6).

6. Laciniated dahlias (LC, 5)

Laciniated Dahlias have the skinniest tubular petals of all the cactus-like dahlia types. The numerous petals are very thin, giving this type a pom-pom shape. They really do sometimes look like they belong on top of a knitted winter hat! Here are some lovely Laciniated-type dahlia varieties:

• Nadia Ruth Dahlia
• Pineland’s Princess Dahlia
• Sassafrass Dahlia
• Myrtle’s Folly Dahlia

Laciniated Dahlias are well-suited to specialty arrangements that aren’t overly formal. Laciniated Dahlias are given the classification code “LC” (think of the code as “Laciniated Cactus”) and the classification number “5” (preceded by a size classification number #1-6).

7. Ball dahlias (BA, 60)

Ball Dahlias are puffy rounded dahlias with neatly-arranged layers of uniform rounded petals in flower heads larger than 3.5” wide. This near-spherical type is one of the most popular types of dahlias due to their uniform appearance and long vase life as cut flowers.

• Jowey Winnie Dahlia
• Black Diamond Dahlia
• Skipley Lois Jean Dahlia
• Andrea Lawson Dahlia

Ball Dahlias can be similar in appearance to Formal Decorative types, but the Ball Dahlias have shorter cupped petals that are so perfectly arranged that they almost look like they were computer-generated. Ball Dahlias are given the classification code “BA” and the classification number “60”.

8. Miniature Ball dahlias (MB, 61)

Miniature Ball Dahlias, or MiniBall Dahlias, are simply small versions of Ball Dahlias that measure 2″-3.5″ wide. These smaller Ball-type flowers are also nearly round and have a puffy cheery appearance.

• Natal Dahlia
• Camano Zoe Dahlia
• Genova Dahlia
• Hollyhill Miss White Dahlia

Miniature Ball Dahlias are wonderful on their own in a vase or among larger flowers in an arrangement. Miniature Ball Dahlias are given the classification code “MB” and the classification number “61”.

9. Pompon dahlias (P, 62)

Pompon Dahlias are tiny Ball-type dahlias with a size diameter of less than 2″ wide. Like MiniBall types, Pompon Dahlias are wonderful displayed all on their own in a vase or used as a filler flower in a larger arrangement. Here are some adorable Pompon-type dahlia varieties:

• Rocco Dahlia
• Moor Place Dahlia
• Bowen Dahlia
• Zippity Do Da Dahlia

Pompon Dahlias are given the classification code “P” and the classification number “62”.

10. Stellar dahlias (ST, 70)

Stellar Dahlias are a specialty type of dahlias with pointed triangle-shaped petals. The petals tend to curl slightly inwards at the base, giving the flower a star-like appearance. Here are some wonderful Stellar-type dahlia varieties:

• Dancin’ Queen Dahlia
• Bloomquist Pumpkin Dahlia
• Ms. Prissy Dahlia
• Clearview Lila Dahlia

Stellar Dahlias are given the classification code “ST” and the classification number “70”.

11. Micro Stellar dahlias (MST, 71)

Micro Stellar Dahlias are Stellar-type flowers with a diameter less than 2″ wide. There are not currently any ADS-registered varieties that meet this definition. Micro Stellar Dahlias are given the classification code “MST” and the classification number “71”.

12. Waterlily dahlias (WL, 73)

Waterlily Dahlias are a specialty dahlia type with saucer-like cupped petals. The gently-rounded petals do have a slight point, but the flowers have a soft and delicate waterlily-like appearance. Here are some beautiful Waterlily-type dahlia varieties:

• Karma Lagoon Dahlia
• Gerrie Hoek Dahlia
• Glory of Heemstede Dahlia

Waterlily Dahlias are given the classification code “WL” and the classification number “73”.

13. Micro Waterlily dahlias (MWL, 74)

The Micro Waterlily Dahlia is a new type of dahlia with waterlily-type flowers less than 2″ wide. There are currently only a couple of registered varieties of Micro Waterlily Dahlias:

• Etoile de Wensel Dahlia (7403, MWL-OR)
• Suitzus Julie Dahlia (7408, MWL-L)

This newer type resembles classic Waterlily Dahlias (WL), just in a tiny form. Micro Waterlily Dahlias are given the classification code “MWL” and the classification number “74”.

14. Novelty Fully Double dahlias (NX, 76)

The Novelty Fully Double Dahlia category is compromised of unique varieties with many petal layers that tend to be symmetrical but do not fit into another form-type classification. The center petals tend to be tightly folded into a ball-like shape while the outer petal layers spread out around the center. Here are some Novelty Full Double varieties to consider:

• Vista Mini Dahlia
• Poodle Skirt Dahlia
• Gitty Up Dahlia
• Puff-N-Stuff Dahlia

The petals of Novelty Fully Double flowers are arranged differently than the common form-type categories. Novelty Fully Double Dahlias are given the classification code “NX” and the classification number “76”.

15. Micro Novelty Fully Double dahlias (MNX, 77)

The Micro Novelty Fully Double Dahlia is a new type category for small Novelty Fully Double Dahlia with a diameter of less than 2″ wide. There are not currently any commercial varieties of this type available for purchase. Micro Novelty Fully Double Dahlias will be given the new classification code “MNX” and the classification number “77”.

16. Peony dahlias (PE, 80)

Peony Dahlias are a specialty type of dahlia flower with open, peony-like flowers. This type has between 2-5 layers of petals around the center. The petals are slightly cupped and somewhat flat.

• Pinky Dahlia
• Stillwater Raspberry Dahlia
• Lake Hills Creamsicle Dahlia

Peony Dahlias are given the classification code “PE” and the classification number “80”.

17. Micro Peony dahlias (MPE, 81)

Micro Peony Dahlias are a newer type of dahlia with small peony-type blooms that are less than 2″ in diameter. These tiny types look almost like double cosmos flowers. There are only about a dozen cultivars available of this type, including:

• Brenda Sue Dahlia
• Elvira Dahlia
• Granville Dahlia
• Jac’s Erin Dahlia
• Miss Muffet Dahlia

Micro Peony Dahlias are given the classification code “MPE” and the classification number “81”.

18. Anemone dahlias (AN, 82)

The Anemone Dahlia category is a unique class of dahlias with a fluffy puff-ball center surrounded by flat outer petals. These flowers don’t necessarily look like dahlias, and truly do resemble anemone flowers with an added dome-like center. Here are some lovely Anemone-type dahlia varieties:

• Blue Bayou Dahlia
• Dad’s Favorite Dahlia
• Boogie Woogie Dahlia

Anemone Dahlias are given the classification code “AN” and the classification number “82”.

19. Micro Anemone dahlias (MAN, 83)

The Micro Anemone Dahlia class is a new category for tiny anemone-type flowers with a diameter of less than 2″ wide. There are no varieties of this type currently available for sale. Micro Anemone Dahlias will be given the classification code “MAN” and the classification number “83”.

20. Novelty Open Center dahlias (NO, 86)

The Novelty Open Center Dahlia category is comprised of unique varieties with visible open disc centers surrounded by outer rings of petals. Like the Novelty Double (NX) class, this type includes varieties that don’t fit into the more structured category types. Here are some lovely varieties of Novelty Open Center-type dahlia varieties:

• Hy Zizzle Dahlia
• Alpen Blush Dahlia

Novelty Open Center Dahlias are given the classification code “NO” and the classification number “86”.

21. Micro Novelty Open Center dahlias (MNO, 87)

Micro Novelty Open Center Dahlias are simply tiny versions of Novelty Open Center Dahlias, with a diameter under 2″ wide. There is currently only one available ADS-registered variety of this type:

• U2 Ania Dahlia (8705, MNO-DP)

Micro Novelty Open Center Dahlias are given the classification code “MNO” and the classification number “87”.

22. Collarette dahlias (CO, 90)

Collarette Dahlias are a unique dahlia type with an outer layer of flattened petals and an inner ring of ruffled petaloids around the center. The inner petaloids appear to give the open center a “collar” – hence the name of this type of dahlia.

• Kelsey Annie Joy Dahlia
• Pooh Swan Island Dahlia
• Night Butterfly Dahlia
• Bumble Rumble Dahlia

Collarette Dahlias are given the classification code “CO” and the classification number “90”.

23. Micro Collarette dahlias (MCO, 91)

Micro Collarette Dahlias are collarette-type flowers with a diameter of less than 2″ wide. This is a newer type with over a dozen registered cultivars, including:

• Cher Ami Dahlia
• Jac’s Banjoy Dahlia
• Kelsey Spirit Dahlia
• Sungate’s Avery Dahlia
• U2 Drew Dahlia

Micro Collarette Dahlias are given the classification code “MCO” and the classification number “91”.

24. Orchid dahlias (O, 92)

Orchid Dahlias are a specialty dahlia type with a single ring of curled cactus-type petals. The star-like petals are evenly space and roll upward and inwards toward the open center. Orchid Dahlias have pointed flowers that resemble spokes on a bicycle wheel. Here are some Orchid-type dahlia varieties:

• Verrone’s Obsidian Dahlia
• Honka Fragile Dahlia
• Bloomquist Trophy Dahlia

Orchid Dahlias are given the classification code “O” and the classification number “92”.

25. Micro Orchid dahlias (MO, 93)

The Micro Orchid Dahlia category is a new type are orchid-type dahlia blooms with a diameter less than 2″ wide. There is only one ADS registered variety as of 2021:

• Cobequid Celestial Star (9302, MO-Y)

Micro Orchid Dahlias are given the classification code “MO” and the classification number “93”.

26. Orchette dahlias (OT, 94)

Orchette Dahlias are designer-type dahlia with slightly curled petals (similar to Orchid Dahlias) but with an added inner layer of petaloid around the center (similar to Collarette dahlia). Here are some Orchette-type dahlia varieties:

• Fancy Pants Dahlia
• Kite Runner Dahlia
• Verrone’s Morning Star Dahlia

Orchette Dahlias are given the classification code “OT” and the classification number “94”.

27. Micro Orchette dahlias (MOT, 95)

The Micro Orchette Dahlia category is for tiny versions of Orchette Dahlias with a diameter of less than 2″ wide. There are no commercially-available dahlia varieties in this new micro category. Micro Orchette Dahlias will be given the classification code “MOT” and the classification number “95”.

28. Single dahlias (S, 96)

Single Dahlias are dahlia flowers with a single row of petals that tend to lay flat. The daisy-like petals overlap uniformly and may be totally flat or slightly cupped. Here are some Single-type dahlia varieties:

• Windmill Dahlia
• Waltzing Mathilda Dahlia
• Alpen Sparkle Dahlia

Single Dahlias are given the classification code “S” and the classification number “96”.

29. Mignon Single dahlias (MS, 97)

Mignon Single Dahlias are micro versions of single dahlias with a diameter less than 2″ wide. The petal tips tend to be more rounded than the larger single types. While many of the micro classes (diameter less than 2″ wide) have few available varieties, the older Mignon Single type has over a hundred available varieties, including:

• Pulp Fiction Dahlia
• Bambino Dahlia
• Sungate First Dahlia

Mignon Single Dahlias are given the classification code “MS” and the classification code “97”.

Source: American Dahlia Society

Dahlia’s color categories & classification codes

The American Dahlia Society classifies all dahlias by color. There are currently 16 color type categories for dahlia flowers:

• White (W): 01
• Yellow (Y): 02
• Orange (OR): 03
• Pink (PK): 04
• Dark Pink (DP): 05
• Red (R): 06
• Dark Red (DR): 07
• Lavender (L): 08
• Purple (PR): 09
• Light Blend (LB): 10
• Bronze (BR): 11
• Flame Blend (FB): 12
• Dark Blend (DB): 13
• Variegated (V): 14
• BiColor (BI): 15
• Black (BK): 16

No registered varieties of the Black (BK, 16) color type are available yet.

Source: Color – American Dahlia Society Online Classification System

Dahlia size categories & classification codes

The American Dahlia Society classifies large dahlias by size. There are currently 6 different size categories for dahlias, according to their new Online Classification Guide (OCG):

• Giant (AA): over 10″ wide (number 0)
• Large (A): 8″-10″ wide (number 1)
• Medium (B): 6″-8″ wide (number 2)
• Small (BB): 4″-6″ wide (number 3)
• Miniature (M): up to 4″ wide (number 4)
• Micros (MC): up to 2″ wide (number 5)

Source: Online Classification Guide, American Dahlia Society

The ADC previously included 10 size categories in their Classification and Handbook of Dahlias. While the larger size categories were the same, there were additional types based on both size and general shape:

• Giant Dahlias (AA): Over 10″ in diameter
• Large Dahlias (A): Over 8″ to 10″ in diameter
• Medium Dahlias (B): Over 6″ to 8″ in diameter
• Small Dahlias (BB): Over 4″ to 6″ in diameter
• Miniature Dahlias (M): Up to 4″ in diameter
• Ball Dahlias (BA): Over 3.5″ in diameter
• Miniature Ball Dahlias (MB): Over 2″ to 3.5″ in diameter
• Pompon Dahlias (P): Up to 2″ in diameter
• Single Dahlias (S): Over 2″ in diameter
• Mignon Single (MS): Up to 2″ in diameter

Source: Size – American Dahlia Society Classification and Handbook of Dahlias