How to propagate dahlias

Every gardener knows that buying plants is a very expensive business. Luckily, nature has a very clever way of enabling us to keep our costs down as it is entirely possible to propagate dahlia plants very successfully. To propagate simply means taking part of an existing plant to create a new, separate plant. The new plant will be genetically identical to the original plant. In the case of dahlias, propagation can be done by seed, taking cuttings or by splitting tubers. Dividing the tubers (roots) is by far the most straightforward method of propagating dahlias, giving good results almost every time if done correctly.

Here is a simple guide to propagating tubers of dahliasPropagating Dahlias

1. Cut the stems of the dahlia right back when the plant is fading or the frosts have come. Leave the plant for about 10 days in order that it grows new small shoots or eyes on the tubers.

2.  After ten days have passed, dig the tubers out, taking great care not to dislodge the new shoots. It is best to dig at least 12 inches down.

3. Clean the tubers gently with water and remove as much soil as possible. Leave the cleaned tuber in a cool, dry place to dry out overnight.

4. The next day, you can divide the tubers. Use a very sharp, clean knife to cut portions of the tuber and ensure that each piece has a new shoot or eye on it. Remove and discard any damaged pieces and pieces that have no new shoots on it.

5. Cover the newly cut tubers in vermiculite or peat and store in a cool, dry place where frost cannot penetrate or the tubers can become frozen. Check on them from time to time during the winter months and dampen the vermiculite or peat if they are starting to look shrivelled.

6. Plant the tubers out in the spring when the threat of frost is over. Pick the healthiest looking specimens to plant and enjoy your free blooms in the summer!


It is also quite simple to take cuttings from dahlias to produce more of your favourite specimens.  Choose strong, healthy shoots about 3 inches long and remove them with a small section of the parent tuber.

Always use a very clean, sharp knife for this task. Place the cutting on a flat surface and remove the lowest leaves. Make sure they are removed as close to the stem as possible. Trim the bottom of the cutting to leave a neat appearance. Take some hormone rooting powder and dip the bottom of the cutting into it, then place it in a small pot of suitable compost, about 1 inch deep.

Place another two cuttings in the same pot and then cover with a clear plastic bag secured by an elastic band. They will form roots within a month, so split them and pot them separately. Keep them watered and plant out in the garden when the frosts are over.