How do you plant dahlias?Updated 19 days ago

How to grow dahlias

Dahlia tubers should be potted up into 15-20cm diameter pots with multipurpose compost between late February and early June. The earlier in spring you can plant them, the sooner they will develop and start flowering in summer. 

The tubers should be submerged in the soil. The point where the tubers are joined at the top should be level with the soil surface. If there is a stump (past year's stalk), this can be left slightly exposed above the soil surface. Water after planting and ensure the water can drain freely from the pot. Position in bright, frost-free conditions to grow on. You should water whenever the compost feels dry below around 3cm from the surface, even if it hasn't sprouted yet. The soil should not be consistently wet. 

Once the dahlia has grown to around 20-30cm tall and it easily comes out of the pot with the soil held together by the roots, it is ready to transfer into a border providing risk of frost has passed. Allow the soil to dry out slightly before removing the plant from the pot as this will help to prevent the soil falling away from the roots and causing damage during transfer. Once transferred into a clear space in a cultivated border, water in and position a cane in the soil next to the dahli in case it needs support later in the season.

Read step-by-step instructions: how to plant dahlias