When it comes to creating a spectacular summer garden, few plants can rival the dahlia. Bursting into bloom from mid-summer until the first frosts, dahlias are loved for their incredible range of colours, flower shapes and sizes. Whether you prefer bold, dinner-plate blooms or delicate pompom varieties, there's a dahlia to suit every garden style.

Not only do they provide months of vibrant colour outdoors, but dahlias also make exceptional cut flowers, bringing the beauty of the garden into your home.

If you're wondering how to grow dahlias, how to keep dahlias flowering, or how to make dahlias last in a vase, you've come to the right place. Here's everything you need to know to enjoy these stunning summer favourites.

Why Are Dahlias So Popular?

It's easy to see why dahlias have become one of the UK's favourite summer flowering plants.

Their popularity comes down to three things:

• An incredible choice of colours, from soft pastels to rich burgundy and vibrant oranges.
• A huge variety of flower forms, including cactus, decorative, pompom, ball, waterlily and single-flowered varieties.
• A long flowering season, blooming from July right through until the first autumn frosts.

Whether you're filling borders, planting containers or creating a cutting garden, dahlias reward you with continuous flowers throughout the summer.

 

How to Grow Healthy Dahlias

Growing healthy dahlias is easier than you might think. With the right conditions, they'll reward you with an abundance of blooms for months.

Choose a sunny spot

Dahlias thrive in full sun, ideally receiving at least six hours of direct sunlight each day. The more sunshine they receive, the more flowers they're likely to produce.

Plant in well-drained soil

Rich, fertile soil that drains well is ideal. If your soil is heavy clay, adding compost or organic matter before planting can help improve drainage.

Water regularly

Once established, dahlias appreciate consistent watering, especially during hot, dry spells. Aim to water the soil around the base of the plant rather than soaking the foliage.

Feed for more flowers

To encourage continuous blooming, feed your dahlias every two to three weeks with a high-potash fertiliser once flower buds begin to appear. This helps support strong stems and plenty of colourful blooms.

Support taller varieties

Many decorative and dinner-plate dahlias produce large flowers on tall stems, so staking them early helps prevent damage from wind and heavy rain.

How to Keep Dahlias Flowering All Summer

One of the biggest questions gardeners ask is:

"How do I keep dahlias flowering?"

The answer is surprisingly simple...

Keep cutting them.

Regular deadheading and cutting encourage the plant to produce even more flowers. Instead of allowing blooms to fade and set seed, the plant directs its energy into producing fresh buds.

To keep your dahlias looking their best:

• Remove faded flowers regularly.
• Cut stems back to a pair of healthy leaves.
• Continue feeding every few weeks.
• Water during prolonged dry weather.

There's a saying among dahlia growers:

"The more you cut, the more they flower."

Thankfully, it's absolutely true.

 

Why Dahlias Make Some of the Best Cut Flowers

If you love fresh flowers in your home, dahlias deserve a place in your cutting garden.

With their striking colours and impressive blooms, they're perfect for creating eye-catching arrangements that brighten any room.

How to cut dahlias for the vase

For the longest-lasting flowers:

• Cut blooms early in the morning or later in the evening.
• Choose flowers that are fully open, as dahlias won't continue opening after being picked.
• Use clean, sharp secateurs.
• Remove any leaves that would sit below the waterline.
• Place stems into fresh water as soon as possible.

How to make dahlias last longer indoors

To enjoy your blooms for as long as possible:

• Change the vase water every two to three days.
• Re-cut the stems slightly each time you refresh the water.
• Keep arrangements away from direct sunlight and radiators.
• Remove any fading flowers promptly.

Most dahlia blooms will last around five to seven days indoors, with some varieties lasting even longer when cared for properly.

One of the joys of growing dahlias is that cutting flowers actually encourages the plant to produce more, meaning you can enjoy fresh bouquets all summer long without reducing the display in your garden.

 

Can You Grow Dahlias in Pots?

Absolutely.

Dahlias grow exceptionally well in containers, making them perfect for patios, balconies and smaller gardens.

For the best results:

• Choose a large container with good drainage.
• Use high-quality compost.
• Position the pot somewhere sunny.
• Water more frequently than plants growing in borders.
• Feed regularly throughout the flowering season.

Compact and patio varieties are particularly well suited to container growing, offering months of colour in even the smallest outdoor spaces.

 

Do Dahlias Attract Bees and Butterflies?

Yes... but it depends on the variety.

Single-flowered dahlias are excellent for bees, butterflies and other pollinating insects because their pollen and nectar are easy to reach.

Some highly double-flowered varieties are bred more for their spectacular appearance, making it harder for pollinators to access the centre of the flower.

If you're creating a wildlife-friendly garden, consider mixing single-flowered dahlias with other pollinator favourites such as lavender, salvias and verbena for a garden that's beautiful and buzzing with life.

 

Frequently Asked Questions About Dahlias

Do dahlias come back every year?

Yes, dahlias are tender perennials. In milder parts of the UK, they may survive winter with protection, but many gardeners lift and store the tubers after the first frost before replanting them the following spring.

How often should I water dahlias?

Water deeply during dry weather rather than giving little and often. Container-grown dahlias may need watering every day during hot spells.

Can dahlias grow in shade?

Dahlias perform best in full sun. While they can tolerate light shade, fewer flowers are likely to be produced.

When do dahlias flower?

Most dahlias begin flowering in July and continue until the first autumn frosts, making them one of the longest-flowering plants in the garden.

Are dahlias easy to grow?

Yes! With plenty of sunshine, regular watering and occasional feeding, dahlias are surprisingly easy to grow and reward gardeners with spectacular displays.

Visit Our Dahlia Festival

There's no better time to fall in love with dahlias than when they're at their absolute peak.

As these stunning blooms reach their finest display, we're celebrating with our Dahlia Festival, showcasing a spectacular collection of colours, shapes and varieties to inspire every gardener.

Whether you're looking for ideas for your own borders, searching for the perfect variety to take home, or simply want to enjoy one of summer's most beautiful flowers, we'd love to welcome you.

Our knowledgeable team will also be on hand to offer advice on choosing, planting and caring for dahlias, helping you enjoy spectacular displays year after year.

We hope to see you there!