The Ultimate Guide to Dahlia Flower Shapes: Understanding the Different Types of Dahlias

Dahlias are one of the world's most diverse and spectacular flowering plants. Originally native to Mexico and Central America, they have become a favourite of gardeners across New Zealand thanks to their extraordinary range of colours, sizes, and flower forms.

One of the most fascinating aspects of growing dahlias is discovering the incredible variety of flower shapes available. In fact, there are over a dozen officially recognised dahlia flower classifications, ranging from tiny pompon blooms the size of a golf ball to enormous dinner plate varieties exceeding 30cm across.

Whether you're planting your first dahlia tuber or expanding an existing collection, understanding the different flower forms will help you choose varieties that suit your garden style, growing conditions, and personal taste.

Quick Guide to Dahlia Flower Shapes

Flower Type	Typical Flower Size	Best For	Pollinator Friendly
Decorative	10–25cm	Garden displays	Low
Dinner Plate	20–30cm	Statement plants	Low
Ball	5–15cm	Cut flowers	Low
Pompon	2–5cm	Borders & bouquets	Low
Cactus	10–20cm	Dramatic displays	Low
Semi-Cactus	10–25cm	Garden impact	Low
Waterlily	8–15cm	Elegant gardens	Moderate
Anemone	5–12cm	Cottage gardens	High
Collarette	5–10cm	Pollinator gardens	Very High
Single	5–12cm	Wildlife gardens	Very High
Peony	8–15cm	Informal planting	High
Orchid/Star	5–12cm	Unique displays	Moderate

Decorative Dahlias

Decorative dahlias are perhaps the most recognisable and widely grown dahlia type in the world. They produce fully double flowers with broad petals arranged in multiple layers, creating lush, luxurious blooms that make a dramatic statement in any garden.

Decorative dahlias are divided into two subcategories: formal decorative and informal decorative. Formal decorative varieties have perfectly arranged petals, while informal decorative types have slightly twisted or irregular petal arrangements that create a softer appearance.

These dahlias are particularly popular because they combine large flower size with excellent garden performance. Many produce dozens of blooms over a season and perform exceptionally well in New Zealand's climate.

Best for:

• Show gardens

• Cut flowers

• Garden focal points

• Beginners

Advantages:

• Huge range of colours

• Long flowering season

• Excellent garden performance

• Stunning cut flowers

Potential drawbacks:

• Larger varieties require staking

• Heavy blooms can suffer in strong winds

Popular decorative varieties:

• Café au Lait

• Thomas Edison

• American Dawn

• Arabian Night

• Spartacus

Decorative Dahlia - Sylvia

Dinner Plate Dahlias

While "Dinner Plate" isn't an official classification, it is perhaps the most famous dahlia category among gardeners. These giant flowering varieties typically belong to the decorative or semi-cactus classes and produce flowers that can exceed 30cm in diameter.

Dinner plate dahlias create incredible visual impact. A single bloom can dominate an entire bouquet or become the centrepiece of a garden bed.

However, these spectacular flowers come with additional requirements. They typically need strong staking, regular feeding, and protection from heavy wind and rain.

Dinnerplate Dahlia - Ottos Thrill

Best for:

• Statement gardens

• Exhibition growing

• Wedding flowers

• Photography gardens

Advantages:

• Massive blooms

• Incredible visual impact

• Highly sought after by florists

Potential drawbacks:

• Require staking

• Lower bloom numbers than smaller varieties

• More susceptible to weather damage

Popular dinner plate varieties:

• Café au Lait

• Emory Paul

• Penhill Watermelon

• Fleurel

• Kelvin Floodlight

Ball Dahlias

Ball dahlias produce beautifully symmetrical flowers composed of tightly arranged petals that curve inward, creating a nearly perfect sphere.

These varieties are favourites among commercial flower growers and florists due to their exceptional vase life, strong stems, and high productivity. Unlike giant decorative varieties, ball dahlias often produce a continuous display of flowers from summer until the first frost.

Their neat appearance also makes them highly versatile in garden design.

Ball Dahlia - Cornel

Best for:

• Cut flower gardens

• Wedding floristry

• Beginners

• Productive gardens

Advantages:

• Excellent vase life

• Strong stems

• High flower production

• Weather resistant

Potential drawbacks:

• Smaller flowers than decorative types

• Less dramatic from a distance

Popular ball varieties:

• Cornel

• Jowey Winnie

• Sylvia

• Ivanetti

• Petra's Wedding

Pompon Dahlias

Pompon dahlias resemble miniature ball dahlias, producing perfectly spherical flowers typically measuring less than 5cm across.

Their compact blooms create a delicate, refined appearance that works beautifully in borders, containers, and floral arrangements.

Despite their small size, pompon dahlias are often among the most prolific flowering varieties available.

Pom Pom Dahlia - Rococo

Best for:

• Container gardening

• Cottage gardens

• Floral arrangements

• Border planting

Advantages:

• Extremely productive

• Long flowering period

• Excellent for bouquets

• Compact growth habit

Potential drawbacks:

• Smaller visual impact

• Can be overlooked in large gardens

Popular pompon varieties:

• Franz Kafka

• Small World

• Sunny Boy

• Little Robert

Cactus Dahlias

Cactus dahlias are instantly recognisable due to their narrow petals that roll backward along most of their length, creating dramatic spiky flowers.

Their unusual shape adds texture and movement to garden displays and creates striking floral arrangements.

Many gardeners become collectors of cactus dahlias because no other flower form offers quite the same dramatic appearance.

Cactus Dahlia - My Love

Best for:

• Dramatic gardens

• Modern landscapes

• Cut flowers

• Collectors

Advantages:

• Unique appearance

• Excellent visual texture

• Large range of colours

• Strong garden performance

Potential drawbacks:

• Some varieties require staking

• Can appear less formal

Popular cactus varieties:

• Park Princess

• Kennemerland

• My Love

• Karma Fuchsiana

Semi-Cactus Dahlias

Semi-cactus dahlias combine the broad petals of decorative dahlias with the dramatic points of cactus varieties.

Their petals remain broader at the base before tapering and rolling backward toward the tip. This creates flowers that are both elegant and striking.

Many experienced growers consider semi-cactus dahlias to offer the best balance between beauty and practicality.

Semi Cactus Dahlia - Tsuki Yori No Shisha

Best for:

• Mixed gardens

• Cut flowers

• Exhibition growing

• Feature planting

Advantages:

• Highly ornamental

• Excellent flower production

• Dramatic without being extreme

Potential drawbacks:

• Often require staking

• Large varieties need more space

Popular varieties:

• Mingus Joshua

• Hollyhill Black Beauty

• Tsuki Yori No Shisha

Waterlily Dahlias

Waterlily dahlias produce elegant blooms with broad, slightly cupped petals arranged in a flattened shape resembling aquatic waterlilies.

These dahlias are prized for their sophistication and are favourites among floral designers due to their graceful appearance.

Their blooms often photograph exceptionally well and bring a softer aesthetic than many other dahlia forms.

Waterlily Dahlia - Karma Choc

Best for:

• Elegant gardens

• Wedding flowers

• Exhibition growing

• Cottage gardens

Advantages:

• Refined appearance

• Excellent cut flowers

• Highly photogenic

Potential drawbacks:

• Less dramatic than giant varieties

• Some varieties flower less prolifically

Popular varieties:

• Karma Choc

• Rancho

• Creme de Cognac

• Gitts Perfection

Anemone Dahlias

Anemone dahlias feature one or more outer rows of petals surrounding a dense cushion-like centre composed of tubular florets.

This unusual structure creates a playful and distinctive appearance that stands out in mixed plantings.

Their partially open flowers also provide greater value for pollinators than many fully double varieties.

Anemone Dahlia - Richards Fortune

Best for:

• Cottage gardens

• Pollinator gardens

• Mixed borders

Advantages:

• Unique appearance

• Pollinator friendly

• Excellent garden plants

Potential drawbacks:

• Less common and sometimes harder to source

• Smaller flower size

Popular varieties:

• Totally Tangerine

• Blue Bayou

• Boogie Woogie

• Polka

Collarette Dahlias

Collarette dahlias feature a ring of large outer petals surrounding a distinctive collar of smaller inner petals.

This creates a layered appearance that is both ornamental and highly attractive to bees and beneficial insects.

For gardeners wanting beautiful dahlias that also support pollinator populations, collarettes are among the best choices available.

Collarette Dahlia - Pooh

Best for:

• Wildlife gardens

• Cottage gardens

• Pollinator planting

Advantages:

• Excellent for bees

• Unique appearance

• Easy to grow

Potential drawbacks:

• Smaller blooms

• Less suitable for formal displays

Popular varieties:

• Pooh

• Night Butterfly

• Impression Fantastico

• Teesbrooke Audrey

Single Dahlias

Single dahlias are among the simplest yet most beautiful dahlia forms.

Their flowers consist of a single ring of petals surrounding an open centre rich in pollen and nectar. This makes them one of the best dahlia types for attracting bees, butterflies, and other beneficial insects.

Single dahlias also tend to flower heavily and require less maintenance than some giant varieties.

Single Dahlia - Happy Single Romeo

Best for:

• Wildlife gardens

• Beginners

• Informal landscapes

• Pollinator planting

Advantages:

• Excellent pollinator support

• Very floriferous

• Easy to maintain

Potential drawbacks:

• Less dramatic blooms

• Shorter vase life

Popular varieties:

• Bishop of Llandaff

• Happy Single Flame

• Waltzing Mathilda

• Moonfire

Peony Dahlias

Peony dahlias bridge the gap between single and decorative varieties.

They feature several rows of petals surrounding an open centre, creating a softer, more natural appearance than fully double forms.

Their open structure provides excellent pollinator access while still delivering substantial visual impact.

Best for:

• Cottage gardens

• Pollinator gardens

• Naturalistic planting

Advantages:

• Beautiful natural appearance

• Pollinator friendly

• Easy to grow

Potential drawbacks:

• Less formal appearance

• Less common availability

Orchid and Star Dahlias

Orchid and star dahlias produce narrow, twisted petals that create delicate, star-like flowers.

These varieties often become favourites among collectors because of their unusual appearance and elegant structure.

Although generally smaller than decorative varieties, they provide exceptional visual interest.

Fancy Pants

Best for:

• Collectors

• Specialty gardens

• Floral design

Advantages:

• Extremely unique

• Elegant flowers

• Excellent conversation pieces

Potential drawbacks:

• Smaller blooms

• Less common in garden centres

Formal vs Informal Decorative Dahlias

Many gardeners are surprised to discover that decorative dahlias are further divided into formal and informal categories.

Formal decorative dahlias have petals arranged in precise, symmetrical patterns. Examples include Thomas Edison and Kelvin Floodlight.

Informal decorative dahlias have petals that twist, curve, or overlap more naturally, creating a softer and often more romantic appearance. Café au Lait is perhaps the most famous example.

Neither category is superior—the choice comes down entirely to personal preference.

Dinner Plate Dahlia - Tartan

Which Dahlia Flower Shape Should You Choose?

If you're just beginning your dahlia journey, consider these recommendations:

For beginners: Ball, decorative, and single dahlias.

For giant blooms: Dinner plate and decorative dahlias.

For cut flowers: Ball and pompon dahlias.

For pollinator gardens: Single, collarette, and anemone dahlias.

For dramatic displays: Cactus and semi-cactus dahlias.

For elegant gardens: Waterlily dahlias.

Most experienced dahlia growers eventually discover that growing multiple flower forms creates the most interesting and beautiful garden displays.

Frequently Asked Questions

What is the most popular dahlia flower shape?

Decorative dahlias remain the most popular worldwide due to their enormous variety of colours, sizes, and flower forms.

Which dahlias are best for cut flowers?

Ball and pompon dahlias are generally considered the best cut flowers because of their strong stems and excellent vase life.

Which dahlias attract bees?

Single, collarette, peony, and anemone dahlias are among the best choices for attracting pollinators.

What are dinner plate dahlias?

Dinner plate dahlias are extra-large flowering varieties capable of producing blooms exceeding 20–30cm in diameter.

Which dahlia type is easiest to grow?

Single, decorative, and ball dahlias are generally considered the easiest and most reliable for beginners.

Final Thoughts

One of the greatest joys of growing dahlias is discovering the incredible diversity of flower forms available. Whether you prefer giant dinner plate blooms, perfectly spherical ball flowers, dramatic cactus varieties, or pollinator-friendly singles, there is a dahlia perfectly suited to every garden.

Many gardeners begin by growing one or two varieties, only to discover that collecting dahlias quickly becomes a lifelong passion.

At Green Fingers, we believe the most beautiful dahlia gardens combine multiple flower forms, colours, and heights to create spectacular displays that flower continuously throughout the New Zealand summer and autumn.