Dahlia Types Explained: How to Choose and Grow Dahlias

Dahlias are best known for their large, decorative blooms, but take a closer look at different varieties of dahlia and you'll find elegant, understated flowers, pollinator magnets and outlandish flowerheads that look rather… bizarre. Find out everything you need to know about the 15 types of dahlia in our complete guide.

Dahlias are firmly in fashion, both as cut flowers and decorative border plants. No two dahlias are alike, and with different cultivars offering everything from dramatic, show-stopping blooms to delicate daisy-like flowers, there really is a dahlia for everyone. Whether this is your first year growing dahlias or you're an old hand, possibly the hardest part about growing these gorgeous flowers is choosing which cultivars to grow!

In this guide, I'll cover three methods you can use to select a beautiful combination of dahlia flowers for your garden and explain how to identify the 15 types of dahlias (with examples!). First, let's run through some common questions new gardeners have about dahlias.

 

When do dahlias bloom?

Dahlias flower from July through to October or even November in mild areas. This long flowering period makes them a staple of late summer and autumn borders. Deadheading dahlias is vital to get the most blooms, as this encourages the plant to produce new buds instead of seeds. Deadhead flowers before they die and cut back to a leaf joint further down the stem. 

 

Do dahlias come back every year?

Dahlias are perennial plants, which means they will grow back year after year. However, they are tender plants and may not survive the winter if planted outside in the UK. The safest way to overwinter dahlias is to lift the tubers after the first frost and store them in a cool, dry place until spring. If you prefer to leave your dahlias in the ground, a thick layer of mulch will help protect them from frost, but this may not be enough in a cold or wet winter.

 

How do you grow dahlias successfully?

You can grow dahlias from tubers, seeds or cuttings. The easiest way to grow dahlias is to buy dahlia tubers in spring and pot them up undercover in March or early April. This gives them a head start, so they'll flower earlier. Once all risk of frost has passed and your dahlia is well rooted with a strong stem and multiple sets of leaves, you can plant it outside in a sunny bed.

Dahlias like moist, well-drained soil and shelter from strong winds. You'll need to provide some kind of support for taller varieties. You can also plant smaller varieties of dahlias in containers. Keep your dahlias well watered and feed plants growing in containers.

 

How to choose the right dahlias for your garden

Choosing what to plant in your garden is hard at the best of times, but it's especially challenging when it comes to selecting dahlias. There are too many beautiful varieties! Here are three approaches you can take to create a balanced palate of dahlia flowers for your beds or patio displays.

Option 1: Plan around a single flower

Often, people fall in love with a specific dahlia flower, whether that's a huge "dinner plate" dahlia or an airy single-flowered type. I believe in growing what you love, so if this is the case for you, use your chosen bloom as a starting point for your planting and select companion plants that will show it off to best effect. These might be dahlias (look at the suggested colour palettes below for inspiration) or other flowers, such as cosmos, Verbena bonariensis, salvias and echinacea. 

Option 2: Choose a colour scheme

Dahlias come in pretty much every colour, except true blue. You can select a harmonious combination of flowers or different varieties that offer dramatic contrast. To make this easier, when searching for dahlia tubers on Gardeners Dream, you can use the filters to display flowers of a specific colour.

Here are some ideas for colour palettes and dahlia varieties to suit your garden:

Peaches & Cream: Soft peach and cream toned flowers, with hints of pale pink, are perfect for wedding bouquets and neutral flower displays. Look at Dahlia 'Free Thought', Dahlia 'Café au Lait', Dahlia 'Hotline', Dahlia 'Wine-Eyed Jill', Dahlia 'Kordessa' and Dahlia 'Kiss'.

Pretty Pastels: Pair purples and pinks with white or cream flowers for a classic cottage garden border. Look at Dahlia 'Lavender Perfection', Dahlia 'Wizard of Oz', Dahlia 'Hollyhill Cotton Candy', Dahlia 'Eveline', Dahlia 'Bishop of Dover', Dahlia 'Lucca Johanna' and Dahlia 'Labyrinth'.

Elegant & Moody: Combine a black dahlia flower with velvety reds, deep purples and jewel pink tones for a dramatic, high-contrast palette. Look at Dahlia 'Arabian Night', Dahlia 'Black Touch', Dahlia 'Thomas A. Edison', Dahlia 'American Dawn', Dahlia ' Rip City' and Dahlia 'Mexican Star'.

Autumnal Warmth: Choose rich, warm oranges, bronzes and reds for a glowing autumn border. Look at Dahlia 'French Can Can', Dahlia 'David Howard', Dahlia 'Brown Sugar', Dahlia 'Noordwijks Glorie', Dahlia 'Sunshine', Dahlia 'Cornel Brons' and Dahlia 'Sylvia'.

Vibrant Colour: Combine vivid reds and yellows or dramatic purples and multi-tone flowers to create an eye-catching display. Look at Dahlia 'Colour Spectacle', Dahlia 'Garden Wonder', Dahlia 'Waltzing Mathilda', Dahlia 'Lake Ontario', Dahlia 'Tartan', Dahlia 'Golden Emblem', Dahlia 'Edinburgh' and Dahlia 'Fringed Star'.

Once you've selected your colour palette, you can move on to look at what size and type of blooms you want (keep reading for more information on dahlia types). This should help you narrow down your options to a reasonable number of varieties.

Option 3: Select plants that suit your garden

Sometimes, having limitations can be a good thing. If you have a patio garden, a tiny spot at the front of a sunny garden, or you want flowers that are beneficial to wildlife, this will narrow the range of suitable dahlias, making choosing what to buy a much more manageable decision!

Most dahlias are tall plants that require staking, so if you're planting dahlias in pots, you'll need to look at more compact varieties, such as Dahlia 'Pretty Woman' or Dahlia 'Totally Tangerine'. You can also grow taller plants with lightweight flowerheads that don't need as much support, for example, single-flowered cultivars like Dahlia 'Sunshine' or star dahlias like 'Honka Fragile'.

It's also worth noting of the height of different varieties if you're filling a spot in a garden bed. Choose shorter varieties for the front or middle of a border, with tall cultivars at the back (or in the centre of a round bed) to create a tiered effect.

Narrow down the choice of dahlia tubers on our website by using the filters to view dahlias of different heights.

 

Types of dahlias

The National Dahlia Society recognises 15 types of dahlias, which I've listed below with examples of each. These categories are sometimes combined by retailers, and you may occasionally find hybrid varieties that overlap two categories. If you like a particular style of flower, it can be helpful to search for these terms and see what varieties come up.

"Dinner plate dahlias" aren't an official classification, but you'll often see the label applied to dahlias with particularly large flowerheads, such as Dahlia 'Café au Lait', 'Labyrinth' and Dahlia 'Thomas A. Edison'.

 

Group 1: Single-flowered dahlias

Single dahlias have daisy-like flowers with a single ring of petals surrounding a central disc. The petals may overlap and can be pointed or rounded. This type of dahlia is a good choice for a bee-friendly garden, as the open centre, packed with nectar-rich florets, makes it easy for pollinators to access nectar and pollen. Examples of single dahlias: Dahlia 'Sunshine', Dahlia 'Bishop of Dover'

 

Group 2: Anemone dahlias

Anemone dahlias have a cluster of large, tubular florets surrounded by one or more rings of flat petals. They look very unusual and are another good dahlia for pollinators and wildlife gardens. Examples of anemone dahlias: Dahlia 'Totally Tangerine', Dahlia 'Blue Bayou'

 

Group 3: Collerette dahlias

Collerette dahlias have a ring of flat, overlapping petals with an inner ring of smaller florets forming a "collar" around the central disc. Due to the open structure, collerettes are loved by pollinators. Examples of collerette dahlias: Dahlia 'Skyfall', Dahlia 'Rhubarb and Custard'

 

Group 4: Waterlily dahlias

These dramatic double flowers bear a superficial resemblance to waterlilies. The broad, saucer shaped blooms may have flat or slightly curved petals. Waterlily dahlias are often shorter and have sturdy stems which may not need support. This also makes them a good choice for growing in containers. Examples of waterlily dahlias: Dahlia 'Lucca Johanna', Dahlia 'Rancho'

 

Group 5: Decorative dahlias

Arguably, all dahlias could be described as decorative, but this specific category is reserved for fully double flowers with broad petals that may be flat or slightly involute (curled inwards). The petals tend to be rounded at the tips, and the flower has no central disc. This is a large, varied category of dahlias, which includes many "dinnerplate" dahlia varieties. Examples of decorative dahlias: Dahlia 'Edinburgh', Dahlia 'Duet'

 

Group 6: Ball dahlias

Ball dahlias have small, rounded petals that are curved inwards along most of their length. The spiral arrangement of the petals gives the flower a spherical shape. The blooms are around 8–15 cm in diameter. Ball dahlias are resilient and last a long time in a vase. Smaller ball varieties, such as Dahlia 'Wizard of Oz', are sometimes called "mini-balls". Examples of ball dahlias: Dahlia 'Red Cap', Dahlia 'Jowey Winnie'

 

Group 7: Pompon dahlias

Commonly misspelled as "pompom dahlias", pompons look similar to ball dahlias, but are smaller in size and structure. The flowerheads have tightly curled petals and are up to 5 cm – the perfect size for a buttonhole or posy arrangement. Like ball dahlias, pompon dahlias last a long time out of water and add a playful feel to beds and flower arrangements. Examples of pompon dahlias: Dahlia 'Franz Kafka', Dahlia 'Moor Place'

 

Group 8: Cactus dahlias

Cactus dahlias have fully double flowers with narrow, pointed petals that curve outwards. The tightly rolled petals give the blooms a spiky appearance that contrasts dramatically with softer blooms. Cactus dahlia flowers vary in size and colour. Examples of cactus dahlias: Dahlia 'Hollyhill Cotton Candy', Dahlia 'Black Narcissus'

 

Group 9: Semi-cactus dahlias

Semi-cactus dahlias are also fully double flowers with outward-curving petals, but they have a softer, fluffier appearance. The base of the flower is broader and the petals are typically rolled at the tip, but flatten out towards the base. Semi-cactus dahlias often have larger blooms than cactus dahlias. Example of semi-cactus dahlias: Dahlia 'My Love', Dahlia 'Rip City'

 

Group 10: Miscellaneous dahlias

There are always a handful of plants that don't fit neatly into a group, hence the need for a "miscellaneous" category. This group includes species dahlias and any other dahlias that don't fit anywhere else. When dahlias were first classified, back in 1966, there were only 10 groups, and you may still sometimes see dahlias in groups 11–15 categorised as "miscellaneous".

Examples of miscellaneous dahlias: Dahlia merckii, Dahlia pinnnata, Dahlia imperialis

 

Group 11: Fimbriated dahlias

The petals on fimbriated dahlias are split at the ends into two or more divisions, giving the blooms a frilly appearance. Aside from the fringing, the petals can be varied and may be flat, curved or twisted. Examples of fimbriated dahlias: Dahlia 'Caproz Josephine', Dahlia 'Myrtle's Folly'

 

Group 12: Star dahlias

This type of dahlia plant used to be called "single orchid", but has since been renamed. Star dahlias have a distinctive appearance, with a single ring of long petals that curl either inward or outward at the tip, surrounding a central disc. Examples of star dahlias: Dahlia 'Honka Fragile', Dahlia 'Verrone's Obsidian'

 

Group 13: Double orchid dahlias

Double orchid dahlias have fully double blooms with layers of lance-shaped petals that may curl inwards or outwards. The flowers have a triangular centre with no disc. The striped 'Giraffe' cultivars are most common in the UK. Examples of double orchid dahlias: Dahlia 'Giraffe', Dahlia 'Jescot Julie'

 

Group 14: Paeony dahlias

These dahlias have multiple rings of flat or slightly curved petals surrounding the disc. The open structure and nectar-filled florets make them a popular flower with pollinators. The paeony group includes many of the popular 'Bishop' cultivars. Examples of peony dahlias: Dahlia 'Bishop of Llandaff', Dahlia 'Waltzing Mathilda'

 

Group 15: Stellar dahlias

Stellar dahlias have only been officially recognised as a separate category since 2017, and they're pretty rare. The striking, fully double blooms have uniformly spaced narrow petals that reflex toward the stem. The petals are slightly curved and pointed at the tip. Examples of stellar dahlias: Dahlia 'Hans Auinger', Dahlia 'Irish Blackheart'