Some of our favourite and most useful garden plants are grown from tubers.
If a tuber produces several growing points, then it can be divided for propagation. Just cut through the tuber, ensuring each piece has an eye, or growing shoot. This method works well with dahlias. The only danger is that the cut surface may rot and destroy the plant. To reduce this risk, either allow the cut section to dry before planting or seal it with fine sand or ash, possibly adding a fungicidal powder too. If several tubers are formed in a season, these may be separated and used to grow new plants. In both cases the new plant will be identical to the parent.
Another propagation method is to start the tuber into growth on a windowsill or under glass. Once new shoots appear, they can be used as cuttings. This is a good way to increase your stock of begonias.
Tubers bought whilst dormant will usually grow easily, the main exception to this is cyclamen. They will often die during storage or take a long time to recover and become established. For this reason, the more expensive growing plants will often prove better value than stored corms even though the initial cost seems lower.
Many popular garden tubers are tender plants and are lifted each year, however if planted deeply in a well drained spot, they often do survive winters outside.
A tuber is a food storage organ which allows the plant to survive from one year to another (much like a bulb or corm). The tuber is actually a swollen root or stem base. Buds or eyes form on the upper surface of the tuber and become the growing shoots. This can easily be seen on a potato which has been stored too long, particularly if it’s been kept in a warm and light place.
With some tubers, such as the potato, the tuber will die away during the growing season, to be replaced with another – or sometimes several new tubers. In others, such as cyclamen, the tuber just grows larger each year.