Stunning floral showpiece has a fascination for the amateur.
AT ONE of my recent Plant Doctor sessions at Armitage's Garden Centres I was reminded by a Mr Harrington about the fascination that this bold summer flower has for a large number of keen amateur gardeners.
Visit any of the mid to late summer flower shows, both national and local, and you will see cut dahlia blooms shown in a wide variety of sizes, styles and colours, that have been grown in back gardens and on allotments all over the country.
The enthusiasm for growing these half-hardy perennials, originally from Central America, started in Britain nearly 200 years ago and, in 1881, the National Dahlia Society (www.dahlia-nds.co.uk) was formed to provide support and help to anyone wishing to grow and show dahlias.
It is still the world's largest dahlia society and helps to ensure that the dahlia, named after Andreas Dahl, a Swedish scientist, still stands large in the perennial cycle of the British gardening year.
To see the flowers at their absolute peak of condition, visit the Harrogate Autumn Flower Show at the Great Yorkshire Show Ground between September 12 and 14 (www.flowershow.org.uk) when the National Dahlia Society will be holding one of its major annual shows. The society will also have a stand for members and non-members alike to get help and support.
The show has 97 classes covering the whole range of dahlia flowers. These flower groups include collerrettes, water lily, peony, orchid, chrysanthemum, anemone, decorative, cactus, semi-cactus, ball and the latest addition of fimbriated flowers where the ray florets are split.
In addition, within each group there are different sizes and hundreds of colour variations, giving more than 55,000 cultivars at the last count. All this from the original 35 species growing in Central America - there's dedication and commitment for you!
Although we can buy dahlias specifically grown for summer bedding, the show dahlias are all grown from root tubers each year or, to be more correct, from shoots produced by the root tubers that have been nurtured over winter by their owners.
The annual cycle of keeping named cultivars true to type and of good stock is a complex affair that has varied little since the 19th century.
In early autumn, unlike most other gardeners, dahlia growers are on the lookout for the first frost that will cut the top growth back overnight - unfortunately, this has not been very forthcoming in recent years and growers have had to lift the plants and cut them back without the help of frosts.
Once the frost has done its job the dahlias can be lifted and the dead flowering stems are then normally cut back to about 150mm (6"), leaving a convenient 'handle' to tie labels to and to carry the tubers around.
The root tubers are left, labelled, in a cool, dark, dry place upside down for 10 days or so to dry out before any surplus soil is removed and the tubers are then put, right way up, into winter storage in a cool, frost free, dark, dry place, usually dusted with flowers of sulphur to keep any dangerous fungal spores at bay.
Some growers will settle the tubers down into dry peat, but this is not really necessary if all other conditions are correct.
In early spring, the tubers are then brought into a bright glasshouse, heated to around 17degC (65degF) and are placed in deep trays or pots of moist peat to initiate new growth from the joint between the old stems and the root tubers.
These new shoots are then used as basal stem cuttings for the new season and it is at this point that growers will be grading out the weak, diseased and poor stock.
Most growers, once the cuttings have rooted and are growing well, will discard the old tubers as they do not produce as strong a growth as the new rooted cuttings - there is often swapping and trading of new season plants at this point, allowing growers to obtain new and different cultivars for their collections.
The new plants are kept at the same temperature until late May when they are hardened off and planted out into their final growing positions in early June in well-prepared ground at about 1 metre (3') apart.
After this, it is just a case of tying, staking, feeding, watering, disbudding, pest and disease watching and preparing for shows, so it is easy, isn't it!
If you want to know more about dahlias, why not visit the National Dahlia Society website or go along to the Harrogate Autumn Flower Show and be amazed at what you see.
FLOWER POWER: What could give more wow factor to your garden than this stunning dahlia and the good news is that there are hundreds more to chose from