Bright, showy dahlias are a highlight of the late summer garden. You can increase your stock by taking basal cuttings from tubers in spring. Each tuber will give you around five new plants for free that will flower in summer.
Be sure to bring the dormant tubers into growth in March, so you can have new shoots sprouting after a few weeks. Once healthy shoots have grown, leave some on the original tuber so that the plant can grow away strongly. Cuttings may wilt initially, but pot them up quickly and water well, and they’ll soon recover.
Rooting will occur after a few weeks, after which you can expect more substantial plants which will need potting on. Harden them off before planting in late spring after the danger of frosts has passed and give young shoots protection from slugs, which love to eat them.
Here’s how to take basal cuttings from dahlias.
You Will Need
- Dahlia tubers
- A sharp knife
- Multi-purpose, peat-free compost
- Seed trays or pots
- Hormone rooting powder
- Horticultural grit
Bring the dormant tubers (which should feel fleshy and firm) into growth. Place them in a shallow tray filled with multipurpose compost. Water well and position in a warm, light spot indoors.
When the shoots are about 8cm long, select a healthy one. Use a sharp knife to cut just above the point where the shoot emerges from the tuber, below the lowest pair of leaves.
Remove the leaves from the lower half of the stem using a sharp knife. Pinch out the growing tip and dip the base of the cutting into hormone rooting power.
Insert each cutting into a small pot filled with potting compost. Firm in, top with grit and water thoroughly. Cover with a plastic bag and place in a warm, light spot out of direct sunlight.