How do I plant dahlia tubers?

Step 1: Choose your favourite dahlia

There are many different types of dahlias to choose from. Start by picking your favourites. Do you prefer white, red or yellow dahlias, or perhaps a different colour? There are also several flower shapes available, such as cactus dahlias, dinnerplate dahlias, pompon dahlias and many others. You can mix and match to create a combination that suits your taste.

Step 2: The right place and the right time

Start with the right location. Dahlias love a sunny spot, so make sure they get at least six hours of sunlight each day. Dahlias are not frost-resistant, so wait until after the last frost to plant them — around mid-May is ideal. Want to get a head start? You can begin pre-sprouting your dahlia tubers indoors in March or April. This not only protects them from slugs but also gives you earlier blooms.

Tip: Read our blog on pre-sprouting dahlias in pots to see how it works.

Step 3: Planting the dahlia tubers

Once you’ve found the right spot, dig a hole deep enough so that the tip of the tuber sits about 2 to 3 centimetres below the surface. This allows the tuber to feel the warmth of the sun. Place the tubers with the stem side facing upwards, and space them about 40 to 50 centimetres apart. Depending on the size and height of the plant, you can place them slightly closer or farther apart. If they are planted too close together, they’ll stretch out and grow tall in search of light. If planting in pots, use only one tuber per pot. For pots with a diameter larger than 45 centimetres, you can plant up to three tubers.

Tip: Read our blog on how many dahlias to plant per square metre for more advice.

Step 4: Covering the tubers

Next, cover the tubers with the soil you removed. You can mix in some organic fertiliser 

to encourage healthy growth. Make sure to water the area well after planting. This will 

help the roots start growing more quickly. Never overwater and wait for the first sprouts to water again.

Step 5: Caring for your dahlias

Within a few weeks, you’ll see the first green shoots appear above the soil, and soon after that, the flowers will start to bloom. Dahlias will continue flowering until the first frost. If the summer is particularly dry, they will appreciate some extra water. However, be careful not to overwater, dahlias don’t like wet feet, and soggy soil can cause the tubers to rot. Make sure your soil is well-drained.

The more flowers you cut, the more the plant will produce. This means double the joy, beautiful flowers both in your garden and in your home. Dahlias are easy to care for overall. Just watch out for slugs.

Step 6: Supporting the plants

As dahlias grow taller, they may need some support. This is often referred to as staking. It helps protect the stems from strong winds and keeps the plants growing upright. Simply place a sturdy stick next to the plant and tie the stem loosely to the stick with a soft tie. This will keep the plant stable and upright, even in windy weather.

Plant support ring for bamboo sticks