Dahlia Flower: How To Grow Dahlias, Planting and Care Tips, Types of Dahlias

Image Credit: Ralph (Ralphs_Fotos)⁴⁸

Dahlia Flower Facts

The Dahlia genus encompasses 42 accepted species of Dahlia Flowers.¹² Dahlias are beloved by gardeners around the world, as they are stunning additions to outdoor and indoor areas. These flowers are fairly easy to grow and are perennials in the right circumstances. The Dahlia Flower may be familiar to most flower growers, but there are several Dahlia Flower facts that may not be well known:

• The Dahlia was first reported growing wild in Mexico in the 16th century, where it was grown and used by indigenous tribes – such as the Aztecs – for various medicinal and practical purposes.^7,10
• The wild Dahlias were noted to be single flowers rather than the double flowers known today. It is thought that modern varieties may have derived from semi-double and double cultivars already growing in indigenous gardens in Mexico and Central America.²⁵
• The garden Dahlia, Dahlia x variabilis, was cultivated from the wild Dahlias and garden Dahlias of Mexico and Central America which were brought to Europe in the late 1700s.²⁵
• The first three species of Dahlias recognized were Dahlia coccinea, Dahlia pinnata, and Dahlia rosea.^{29,30,12,31,23}
• Dahlias quickly became major show flowers across Europe, leading to more and more cultivars and hybrid varieties.²⁵
• The Dahlia has been the Mexico national flower since 1963.¹⁰
• The tubers of Dahlia plants are actually edible and can be harvested in late autumn or early winter.¹⁴
• In some countries, Dahlias are grown almost exclusively for exhibition, while they feature heavily as garden flowers in other regions.²⁵
• Dahlias are excellent plants for large containers, allowing for placement in maximum sun exposure and making it easier to dig up tubers in winter.¹³
• Dahlias proliferate abundantly, and a single tuber is likely to multiply into a clump of tubers by the end of the growing season.⁵
• Dahlia is an incredibly diverse genus with 42 recognized species and many types of classifications and categorizations.¹⁰
• The Dahlia Flower features heavily in pop culture, particularly the black Dahlia Flower. The name “Black Dahlia” was given to a female victim in a famously gruesome 1940s murder case, inspiring subsequent books and movies.²³

Types of Dahlia Flowers and Dahlia Pictures

There seems to be no end to the types of Dahlia Flowers. Dahlias come in more shapes, sizes, forms, and colors than practically any other flower genus. Like most other types of flowers in the Asteraceae family, Dahlias have composite blooms, made up of hundreds of tiny to small flowers.³² This makes the flower heads of the Dahlias splendid in their depth and complexity.

While it may be simple enough to distinguish Dahlias from plants outside the aster family with a quick study of their inflorescence, Dahlia pictures are indispensable in differentiating the many varieties of Dahlia Flower.

(Image: Sid Bhatnagar³⁷)

Dahlia Flowers are usually classified according to their size, form, and color. While some Dahlias have a broad, open bloom, others have a dense, closed flower head.

1. Ball

Ball-shaped Dahlias have tight, rounded forms. They are an easily recognized Dahlia type. Ball-shaped Dahlias fall into one of three groups:

• Pompon: Petite, fully double, flower heads up to 2 inches in a dense ball or lollipop shape.
• Miniature Ball: Larger than pompon, still fully double, the miniature ball varieties have round, ball-shaped blooms ranging from 2 to 3.5 inches in size.
• Ball: Ball varieties also have fully double blooms. They are dense, long-lasting, ball-shaped flower heads of at least 3.5 inches.

* Chart based on ‘Floret Farm’s Discovering Dahlias: A Guide to Growing and Arranging Magnificent Blooms” by Benzakein.⁵

The other forms of Dahlias are less uniform and more diverse, displaying a variety of shapes and sizes. They include the following primary types ⁵

2. Cactus

Cactus Dahlias are fully double, and they are characterized by their long, slender petals which curve backward (revolute) creating a rolled cylindrical look.

(Image: Mariluna³⁸)

The size of cactus Dahlias varies according to the length of the petals. These Dahlia types have a spiny appearance. There are two, true cactus Dahlia types.²⁵

• Incurved Cactus: The incurved cactus has fully revolute petals that arch towards the center of the flower.
• Straight Cactus: The straight cactus has petals that roll inward for at least half of their length with a somewhat flatter petal base. The petals stick out mostly straight or may arc back towards the stem slightly.

3. Cactus-Like

These Dahlias can be difficult to distinguish from cactus types, as they also have a spiky appearance.

(Image: Dinesh Valke from Thane, India³⁹)

Semi-cactus Dahlias are often classed with the cactus Dahlias. Laciniated Dahlias may overlap with other categories. 

• Laciniated: Laciniated Dahlias are fully double with no center disk, resembling cactus types. The many ray petals are thin and delicate, with a spiky, thready appearance. The rolled petals are divided at their tips, creating a feathery look.
• Semi-Cactus: Semi-cactus Dahlias, also fully double, most closely resemble the straight cactus, but the base of the petals is usually flatter and the rolled tip of the petals is less than half the petal length.

4. Decorative

Decorative flowers are popular in flower arrangements and displays, as their full and vivid blooms add depth and texture.

(Image: Cillas⁴⁰)

The two types are differentiated by the regularity of their petals.

• Formal Decorative: This class of Dahlias often has mostly medium to large fully double blooms with petals arranged uniformly. Distal petals are fairly flat, but the more central petals have inward curving edges, creating a scoop shape.
• Informal Decorative – Some of the largest Dahlia varieties are in this class, many bearing giant, ‘dinnerplate’ blooms. The fully double blooms have soft, delicate petals that are flat with pointed tips. The petals of the informal decorative are much less uniform and are in a looser arrangement.^{5, 28}

5. Novelty Types

These types of Dahlias have been grouped under the ‘novelty’ heading because they do not fit readily under other classifications.

(Image: Krzysztof ZIarnek, Kenraiz⁴¹)

These flowers are usually on the small side.⁴

• Novelty Fully Double: Flowers in this group have a tightly closed center and symmetrical outer petals.
• Novelty Open: A collection of rare Dahlia varieties that have open centers of equal size to the outer petals.

5. Orchid

These star-shaped flowers stand out from other types of Dahlias due to their unique, almost bizarre appearance.

(Image: TeunSpaans⁴²)

These flowers often have eight pointed ray florets surrounding the open center disc.⁴

• Orchette: The orchette Dahlia often has eight-pointed, flat to inward rolling petals surrounding an open central disc. Each ray floret has a smaller petal (petaloid) at its base.
• Orchid: These small flowers have inward rolling, pointed petals that are evenly spaced around the open center.

6. Single

The blooms of single Dahlias have only one ring of outer ray petals, usually eight, surrounding the central disc.

The outer petals are mostly flat and uniform, overlapping slightly, usually with rounded tips.

(Image: [email protected]⁴³)

These small flowers are favorites with pollinators.^{4, 28}

• Mignon Single: This is a miniature single flower, no larger than two inches across.
• Single: The inflorescence of these flowers is more than two inches in diameter.

7. Other (With Open Centers)

The Dahlia types in this loosely defined group are pollinator favorites, with open, at least partly, centers accessible to bees and hummingbirds and likely to attract many types of butterflies.

(Image: Marktee1 at English Wikipedia⁴⁴)

These flowers are always miniature or small.⁴

• Anemone: Anemone Dahlias are quite unique among Dahlias. The flowerhead has an open appearance with flat ray petals ringing the central disc. However, the tubular disc flowers are long, dramatic, and dense, making it one of the Dahlia plants that attract hummingbirds.
• Collarette: A collarette Dahlia is a single flowerhead with a bit of extra flair. The center disc is surrounded by approximately eight flattened ray florets, overlapping. Like the orchette, the petals are paired with smaller petaloids that tuft around the central disc. The petaloids are pronounced and should be at least half the size of the ray petals.
• Peony: The open center disc is surrounded by two to five rows of broad, mostly flat ray petals, spaced evenly.

8. Other (With Closed Centers)

These fully double Dahlia varieties are distinct, recognized classifications.

(Image: Marktee1 at en.wikipedia⁴⁵)

These flowers are usually in the small to medium size range.[4]

• Stellar: The stellar Dahlias have long ray florets with pointed tips. The narrow petals curve inward at the base, creating a cup or boat shape, before recurving back towards the stem.
• Waterlily: Arguably the most beautiful of all Dahlia varieties, the waterlily Dahlia resembles members of the Nymphaeceae (water lily) and Nelumbonaceae (lotus) families.^{33, 34} Waterlily Dahlias have a shallow, open face with delicate layers of ray florets surrounding a closed center.

* Charts based on ‘Floret Farm’s Discovering Dahlias: A Guide to Growing and Arranging Magnificent Blooms” by Benzakein, davesgarden.com, and The American Dahlia Society. Color (or colors) is specified for most Dahlia varieties.^1,2,5

Dahlia Flower Colors

The abundance of Dahlia Flower colors also knows no bounds. A Dahlia Flower can be found in practically any color along the entire spectrum, and many colors in between. Dahlia blooms are often multi-colored, with gradually transitioning hues or bold contrasts. A Dahlia garden will feature not only a wide variety of forms but also a myriad of complementary colors.

White Dahlia Flowers

Many types of white flowers commonly used in floral displays for special occasions such as weddings belong to the Dahlia genus.³⁵ The elaborate blooms of Dahlias, which range from delicate to bold, can be selected and arranged to complement wedding decor of any variety. Some favorite white Dahlia Flower varieties include:⁵

• ‘Blizzard’: A formal decorative variety with lush foliage and strong stems.
• ‘Ferncliff Alpine’: Collarette variety with star-shaped single blooms, great for pollinators.
• ‘Platinum Blonde’: Anemone variety with a creamy dense center surrounded by large ray petals.
• ‘Small World’: Miniature ball variety with strong stems and resilient, abundant blooms.¹

Yellow and Orange Dahlia Flowers

Yellow and orange Dahlias are perfect in an outdoor summer garden, adding bright color with wide-ranging hues. Some favorites include:⁵

• ‘Born Sty’: A stellar variety with pale blooms in shades of lemon and peach.
• ‘Ginger Willo’: A pompon variety with burgundy centers surrounded by burnt orange and gold.
• ‘Karmel Korn’: An informal decorative variety with blooms in shades of buttercream and lavender.
• ‘Lucky Ducky’: An anemone variety, single-flowered, with fuzzy centers surrounded by large yellow petals.
• ‘Skipley Moonglow’: A ball variety with buttercream blooms with blushing tones.
• ‘Verrone’s 14-30’: A laciniated variety with medium-sized blooms in subdued orange tones around a green center.

Red Dahlia Flowers

Red Dahlia Flowers are arguably some of the most striking, with their incredible, bold hues, and unique markings setting them apart. These are some favorite red Dahlias:⁵

• ‘AC Rooster’: A stellar variety with red, pointed ray petals.
• ‘Gitty Up’: A novelty fully double variety with a deep red, fuzzy center surrounded by orange rays.
• ‘Lupin Britain’: A pompon variety with red blooms lighter around the edges.
• ‘Santa Claus’: An informal decorative variety with small blooms that have white rays with deep red centers.

Pink Dahlia Flowers

Any type of pink flowers is likely to be featured in an outdoor garden as the color pairs well with most other garden hues. Like the white Dahlias, pink Dahlias are also commonly used in wedding arrangements. Many favorite Dahlias are pink, such as:⁵

• ‘Alloway Candy’: A stellar variety with abundant medium-sized pink blooms.
• ‘Fancy Pants’: An orchette variety with miniature blooms with orange-gold centers and folding pink and white rays.
• ‘Hollyhill Pinkie’: A laciniated variety with miniature blooms in pinkish-purple tones.
• ‘Skipley Lois Jean’: A ball variety with bright pink blooms.

Purple Dahlia Flowers

The realm of purple Dahlia Flowers is varied, boasting blooms in soft, pale tones as well as deep hues. These are some gardener favorites:⁵

• ‘Genova’: A mini ball type with soft lavender blooms with a dark center.
• ‘Koko Puff’: A pompon variety with mauve hues.
• ‘Puff-N-Stuff’: A novelty fully double variety with reflexed reddish-purple rays around a dark, fluffy center.
• ‘Salis Going Dark’: A formal decorative variety with small blooms in hues of lavender and wine.

Black Dahlia Flower

Black Dahlias are favorites wherever they are grown, and many black Dahlia Flowers boast incredible color depth with hues of deep maroon and red. Here are some favorites:⁵

• ‘Black Narcissus’: A laciniated variety with medium spiky blooms that have dark centers and deep red ray petals.
• ‘Jowey Mirella’: A ball variety with dark centers and deep red dense ray petals.
• ‘Natal’: A mini ball variety with dark centers and deep red hues.
• ‘Soulman’: An anemone variety with small blooms in rich maroon tones and reflexed petals.

How To Identify Dahlia Flower

Learning how to identify Dahlia Flowers can be really tricky given the incredible variety within this genus of plants. Dahlias are appreciated for their long, sturdy stems and showy, colorful blooms.

They are also unique to other members of Asteraceae because they are tuberous, growing and multiplying through large, meaty underground roots.

Gardeners can use the previous section on Dahlia forms to learn about the many different varieties of Dahlia.

Identifying Dahlia Leaves

There are a few characteristics of Dahlia leaves that can make these plants easier to identify. Dahlia leaves are typically pinnate or even bipinnate, meaning individual leaves are divided into leaflets which may be further divided. They are usually paired at each node, with terminal leaflets. The texture of the leaves is smooth and slightly waxy, and the edges are typically toothed.³

Identifying Dahlia Seeds

Dahlia seeds are only produced by the central disc florets, and the size of the seeds is proportionate to the size of the flower head. Seeds are elongated and dark, and multiple seeds are enclosed within a seed pod.²⁵

Identifying Dahlia Tubers (Dahlia Bulbs)

Dahlia tubers are often confused with bulbs, but there are no Dahlia bulbs. Dahlias grow a fleshy, modified root underground (a tuber), much like a potato. Dahlia tubers are brown and elongated, with one end markedly more narrow. The tubers have raised bumps, or eyes which can sprout new plant parts.^8,17

How To Grow Dahlias

A garden of Dahlias can be a haven for pollinators and gardeners alike. Learning how to grow Dahlias is an art that involves understanding when, where, and how to plant these flowers for maximal yield year after year.

Dahlia Flower Growing Zone (Where To Grow)

The first step to successful Dahlia growing is knowing the native growing zones for Dahlia Flower: where to grow these stunning plants for plant hardiness and health. The Dahlia Flower growing zones are USDA zones 8 and above.³⁶ In these zones, the Dahlia can be grown as a perennial⁶.
Dahlias can also be successful in planting zones 3 through 8 when:

• Grown as an annual.
• Grown in containers that can be moved indoors during the winter.
• Tubers are dug up and stored in a warm place through winter.

Best Growing Conditions for Dahlias

The best-growing conditions for Dahlia Flowers are in full sun with six to eight hours of direct sunlight.

They like rich, fertile soil that drains well. Given the delicacy of many Dahlia blooms, an area protected from strong winds is also preferable.⁶

When To Plant Dahlias (Dahlia Season)

Summer is the Dahlia season, when abundant blooms adorn the garden, but a gardener needs to know when to plant Dahlias to achieve that breathtaking summer landscape.

Remember that Dahlias are subtropical plants, and they will not withstand frosts or persistently cold ground. Dahlias can usually be started outdoors around the same time as tomatoes, in late spring. They can be started indoors in containers if preferred.¹

Planting Tips for Dahlia Flowers

Here are several planting tips for Dahlia Flowers that can ensure a healthy flower crop:

• Grow larger Dahlias from tubers rather than seeds.
• Choose tubers that are plump rather than shriveled, with visible eyes when possible.
• Plant like-sized (height) Dahlias together.
• Plant whole tubers, eyes up, into a 6” hole and cover with some compost and a couple of inches of soil.
• Skip watering and mulching at planting.⁶

How Far Apart To Plant Dahlias

Dahlia spacing is an important factor in how well Dahlia plants thrive. How far apart to plant Dahlia Flowers depends on the size of the flower and the desired effect.

The large, very tall Dahlias (~ 4 to 6 feet) can be well planted 12 inches apart, where they can create a barrier and provide support for one another. Layer these in rows 3 feet apart for best effect.

(Image: Velvet⁴⁷)

Shorter Dahlias (~ 3 feet tall) can be interspersed throughout a flower garden. Allow 2 feet of space between them at planting. The smallest Dahlias require a foot or less of spacing.⁶

How Long It Takes To Grow Dahlia Flower (Growing a Dahlia Flower From a Seed)

How long it takes to grow Dahlia Flowers depends, to some extent, on the type of Dahlia, but mostly it depends on the growing method. Dahlias grown from healthy tubers will typically sprout within two weeks and bloom as soon as 8 weeks after planting.²²

Growing a Dahlia Flower from a seed takes considerably longer than growing from a tuber, often 3 to 4 months after planting. Also, bear in mind that, unlike tubers, Dahlia seeds will not produce clones of the parent plant.¹⁹

Tips for Growing Dahlias in Containers

Growing Dahlias in containers can be a great place to start, and containers are particularly well-suited to the smaller Dahlia varieties but amenable to the taller varieties as well. Here are a few tips to get started:[²¹

• Choose a sturdy, clean container.
• Ensure the tuber is healthy and plump.
• Fill the container ⅓ of the way with a loose, soil-less potting mix (to lessen the risk of rot).
• Mix in co-polymer crystals, if desired.
• Set the tuber horizontally deep into the container, eyes up, and cover it with a couple of inches of the mix
• Mist lightly if desired, but do not soak.
• Add more potting mix as the plant grows, keeping the roots covered.
• Once the plant is established, water regularly but in moderation.

Caring for Dahlia Plants (Dahlia Care)

Dahlia plants require differing levels of care, but there are a few things that Dahlias have in common.

They need constant sunlight, so plant them in a well-lit place. They like to be fertilized modestly every couple of weeks with a low-nitrogen option.

(Image: Hunter Bloor⁴⁶)

Dahlia care also involves staking larger plants for support. Old blooms should be deadheaded to encourage more growth, and smaller blooms can also be removed to funnel resources toward larger blossoms.⁶

Watering Needs for Dahlia Flower Plants

A young Dahlia plant obtains most of its nutrients from the tuber, but as the plant becomes established and the tuber dies out, the watering needs for Dahlia Flower plants increase.

Once green growth is visible above the soil, the plant should be ready for regular watering. Water Dahlia plants thoroughly at least once a week, more in hot weather. Note that container plants require more water.¹¹

Companion Plants for Growing Dahlias

Some of the best companion plants for growing Dahlia Flowers are herbs such as rosemary and bee balm, other flowers in the daisy family, such as zinnia, coneflower, and black-eyed Susan, as well as root vegetables like onion and garlic. In this way, a gardener can craft their own Dahlia farm.¹⁸

How To Stop Dahlia Diseases

Anyone invested in Dahlia farming has undoubtedly run up against a variety of Dahlia diseases. It is critical that gardeners know how to prevent, how to recognize, and how stop Dahlia Flower disease before it’s too late!

Here are a few diseases that are particularly problematic for Dahlias:²⁰

Bacterial Disease

• Aster Yellows: Leave and blooms become small, pale, and misshapen. Carried by leafhoppers.
  Treatment: Fatal. Remove infected plants.
• Bacterial Wilt: Leaves darken and foliage and petals wilt during the day.
  Treatment: Fatal. Remove infected plants.
• Soft Rot: Leaves develop yellow, wet spots. Odor and soft stems ensue.
  Treatment: Fatal. Remove infected plants.

Fungal Disease

• Botrytis: Gray spores appear on the plant and petals begin browning from their centers.
  Treatment: Non-fatal. Carefully prune and dispose of infected plant parts.
• Powdery Mildew: Gray or white powdered spots appear on leaves. May occur in high levels of humidity.
  Treatment: Non-fatal. Carefully prune and dispose of infected plant parts.
• Smut: Leaves develop pale spots that have darker centers. Lower leaves are typically affected first.
  Treatment: Non-fatal. Carefully prune and dispose of infected plant parts.
• Southern Blight: A ring of fungus appears in the soil around the base of the plant and worsens until it smothers the plant.
  Treatment: Fatal. Remove infected plants.
• Verticillium Wilt: Leaves turn yellow and the stem darkens near its base. Roots may become streaky.
  Treatment: Fatal. Remove infected plants.

Viral Disease

• Dahlia mosaic: Leaves may develop pale green streaks near their veins.
  Treatment: Fatal. Remove infected plants.
• Ring Spot: Leaves become mottled and develop ring-shaped spots. Spread by thrips.
  Treatment: Fatal. Remove infected plants.

Common Pests

Dahlias are known for attracting pests in the garden, and many gardeners choose to plant them next to herbs known for their ability to deter pests. The most troublesome and common pests of the Dahlia Flower include:⁶

• Slugs
• Spider mites
• Earwigs
• Aphids
• Caterpillars
• Nematodes
• Thrips
• Whiteflies

Natural Pest Control For Dahlia Flowers

The best natural pest control for Dahlia Flowers is prevention, and the best way to do this is to keep the flowers healthy and the garden free of weeds and dying flowers. Also, eliminate sources of standing water that may attract pests and avoid mulching around Dahlias with decaying yard litter.

Planting marigolds and lavender nearby can also help deter pests, and some gardeners even suggest using sheep wool or pellets around the base of the flower stalk. In severe cases, insecticidal soaps and oils can be used to eliminate pests.^{, 26}

Growing Dahlias does not have to be difficult, and a little bit of practice pays dividends when those beautiful bright blooms explode in the garden. Use this guide to learn how to grow and care for Dahlias as well as how to recognize many different types of Dahlia Flower.

Frequently Asked Questions About Dahlia Flower