There are three ways to grow dahlias: from tubers, rooted cuttings or seed.
Tubers are the roots of mature plants and look like a cluster of brown, carrot-like roots joined by the previous year’s dried stem. You can buy them from garden centres or by mail order in spring, or use your own tubers that have been overwintered.
If you plant them out before all risk of frost has passed then they may die, so plant the tubers in large pots filled with multi-purpose potting compost in March or early April. Keep them on a windowsill or in a frost-free greenhouse until late May, when it will be safe to plant them outside.
Starting off your dahlia tubers in pots will also encourage them to develop more quickly, so they’re likely to start flowering earlier. Before planting, soak tubers in a bucket of tepid water for an hour so they can fully rehydrate.
Discover how to grow dahlias from tubers with help from this quick guide, below.
You will need
- Dahlia tubers
- Large pots
- Multi-purpose compost
- Plant labels and pen
Total time:
Step 1
When planting, ensure that the joint where the roots meet the stem is facing upwards. Label your pots and grow on in a greenhouse or sunny windowsill. Keep the tubers well watered.
Step 2
Pinch out the tips of the main shoot, down to the top pair of leaves. You also need to remove most of the shoots growing from the tuber, except for five. This encourages bushy plants, strong, vigorous growth and a lot more flowers.
Step 3
When all risk of frost has passed, harden off plants by placing them outside during the day and bringing them in at night. After a week they will be ready to plant out into their final growing positions.
Basal cuttings from dahlias
Once your dahlias have started sprouting, it’s the perfect time to take basal cuttings. It’s a simple process and will provide you with new plants for free.
