How to plant and grow Dahlias

The delights of the Dahlia season are back at Seed Pantry! We cannot be more excited to get these planted. If you need a hand getting your Dahlias started from the Grow Club, here is our grow guide!

When the last frosts are behind us you can go for planting them directly outside in final growing positions – borders or large containers (40cm+ wide). If you plant them early in March, this will help them get a head start and growing, do this in pots around 3 litres in size and keep them frost-free by placing undercover or protected outside. 

How to plant and grow dahlias

1. Generally starting dahlias early should go in containers that you keep frost-free, then plant them out in final positions around mid-May.  Or from May plant them directly where you want them.

2. Plant dahlias with each bunch of tubers generally spread out a little and lying horizontally around 12cm deep, if it’s a tight bunch of tubers simply pop them in at the required depth. Then loosely add general potting compost. You mix in a few handfuls of sand/grit to help with drainage.

3. Cover the tubers, add a splash of water and wait for the magic to happen! Position early plantings outdoors in a frost-free area.  Transplant the early plantings in May to final growing positions in borders or containers.

4. Dahlias can be tall plants with large flowers, at 1m+, some support or stakes may be needed to avoid them toppling over. They need watering regularly during dry summers, every 2/3 days. You can also add a liquid fertiliser every 2 weeks for top-notch flowers that keep on blooming all summer (tomato feed).

Seed Pantry Team