Dahlias can be the star of any garden! A member of the Asteraceae family, Dahlias are originally from the cool highlands in Mexico and Central America.  These dazzling flowers come in all colours except blue. In 1846 the Caledonia Horticultural Society of Edinburgh offered a prize of 2000 pounds to the first person succeeding in producing a blue dahlia. This is yet to be accomplished. Dahlias produce anthocyanin, the element required to achieve a blue colour. The anthocyanin delphinidin needs six hydroxyl groups. So far to date, dahlias have only developed 5 hydroxyl groups. So maybe one day we will see a blue dahlia, science permitting! Dahlias also have a variety of blooms; Anemone-flowered dahlias have large tubular petals; mignons have single flowers on stems.  There are also a variety of bloom sizes from a 2-inch pompon type to a dinner plate size up to 14 inches across.  There are 50,000 registered varieties of this beautiful flower. This is one of the reasons I am so enchanted by them. Each variety is so unique, and the colours are remarkable!

Dahlias are versatile and can be grown from seed, tubers or purchased from a garden centre in a pot. They do prefer a sunny location but can grow in part shade. In partial shade they may not produce to the same wonder as when they are in a sunny spot, but they will try to impress you non-the-less, but with limited blooms. Dahlias are wonderful cut flowers, often used by florists. They can be planted directly in the garden or do very well in pots.

Even though they are considered an annual, their roots can be kept from year to year. Their tuberous nature enables them to survive periods of dormancy. This means that gardeners in climates with frost can grow dahlias successfully if the tubers are lifted from the ground and stored in a cool, frost-free area.  Unfortunately for some, this part of the gardening process seems too onerous. However, it is quite simple to lift the roots out of the ground, cut off the green portions, and brush off as much soil as possible. You can also lightly hose off the soil with a garden hose. Once the tubers are clean, allow them to dry in the sun. Once this part of the process is complete the tubers can be placed in vermiculite, saw dust or peat moss. Some gardeners simply put the dried tubers in newspaper or in a brown bag and store them that way. Once the tubers are ready for storage they should be placed in a cool, dry, dark place to enable dormancy over the winter. For those dahlias bought in pots from the nursery, you can complete the same process.

Once the ground is warm in the spring, the tubers are ready to plant in your garden and that is when the behind-the-scenes magic takes place! If you are willing to take on this task you will be congratulating yourself in summer when your garden is full of these showstoppers.

References:

1. Bennett, J., Forsyth, T., 1990, The Harrowsmith Annual Garden, Camden House, pp 145-146
2. Wikipedia, Edited: 2024/ 10/ 03, Dahlia, http://en.m.wikipedia.org/wiki/Dalhia, 24/10/11
3. Fell, D., 1990, The Essential Gardener, Michael Friedman Group Publishing, p. 237