Dahlias are herbaceous (non-woody stems) perennial plants that grow from tubers. They bloom from around December (depending on the region — later in colder climates) through until autumn, and there is a wide selection of beautiful colours and flower forms to choose from.

When to plant

Spring through to early summer is the recommended time for planting new dahlia tubers. Choose a well-drained site in full sun, sheltered from strong winds, as some dahlias can grow up to 1.5 metres tall.

Dahlias thrive in fertile soil, so prepare your site about a month before planting by digging plenty of compost into the existing soil, particularly if it is heavy clay. Check the packet or with your supplier, as the depth and spacing will depend on the variety you are growing (bedding, medium or tall types). Always plant tubers with the shoots facing upwards. Dahlias can also be grown in pots using Daltons Premium Bulb Mix.

With taller varieties, place stakes in the ground before planting the tubers. As the plants grow, tie them to the stakes regularly to prevent wind damage.

Ongoing care

Once dahlias have produced their first set of leaves, give plants a deep watering three to four times per week during dry periods. To encourage side shoots, pinch out the central growing tip two to three weeks after planting, or when the plant has four sets of leaves.

When plants reach around 15 cm high, mulch with Daltons Premium Much and Feed to help retain moisture and reduce weeds. Apply a light side dressing of Daltons Daltons Garden Time Complete Garden Fertiliser as the plants grow through summer.