My childhood friend Leandro Nunez, who lives in San Francisco, and his wife Dana went strolling with their granddaughter Emilia at the Golden Gate Park near their home last week. Dahlias were in bloom, and the proud grandparents sent me a photo of beautiful Emilia posing among the gorgeous flowers. Dahlia is the official flower of San Francisco, and every year the bountiful flowers attract visitors from far and near during their peak blooming time from June to September.
Native to the mountainous regions of Mexico, where it was called cocoxochitl by the Aztecs, the dahlia has a very peculiar history. In 1789, Vicente Cervantes, the director of the botanical garden at Mexico City, sent tubers to Abbe Antonio Jose Cavanilles, director of the Escorial Royal Gardens in Madrid. Cavanilles managed to make the plants bloom, and named them in honour of Swedish botanist Anders Dahl. However, he was interested not in the flowers but in the tubers, which he thought might be edible like the potato. The plants, however, became the envy among those who saw their flowers at the Escorial gardens.
Either one of the gardeners at the Escorial was bribed or a plant bandit was extremely successful, for a few tubers were taken to Paris and sold to the Jardin des Plantes, but being planted in unfavourable conditions the tubers promptly rotted away. The same happened to the tubers that found their way to England from Mexico.
France’s emperor Napoleon Bonaparte procured some tubers for his wife Josephine, who managed to successfully grow them in her garden at Malmaison. She was extremely jealous of her collection, caring for them herself, until she had so many of them that it was necessary to hire a gardener specially to look after the precious plants. Corruption inevitably followed.
A lady-in-waiting, who had asked for a tuber but was curtly refused, was determined to have a collection of her own and outdo her royal mistress. She and her lover, a Polish prince, bribed the gardener to obtain some of the plants. When the empress learned of this she was outraged and immediately sacked the gardener, dismissed the lady-in-waiting and exiled the prince from the court. In her anger she also had all her dahlias chopped up and buried, and would not hear again of the plant’s name.
It was an expensive waste as dahlias were valuable indeed — in 1836 a diamond was traded for a single tuber — until, from Mexico through a third source, Berlin, they were developed and eventually became more common and cheaper. Cocoxochitl, regarded as a weed in Mexico, had thus come very far, thanks to travellers and plant lovers who were primarily responsible for its now wide distribution.
A member of the Asteraceae or Compositae family of plants that include the aster, chrysanthemum, daisy, sunflower and zinnia, the dahlia comprises 35 species and hundreds of cultivars, with flowers in a wide variety of colours or colour combinations and sizes. Surprisingly, it has never really caught up with other flowering plants like the rose and the gardenia in popularity among Thai growers. At first this was attributed to its Thai name, rak rae, which means “unstable love”. According to Kasetsart University professor Preedee Akavipat, now deceased, who headed research on dahlias, superstitious Thais, especially the wife who was afraid her husband would take up a mistress, thought that the very name of the plant was a bad omen.
To make the plant gain the popularity that it deserved, its name was changed to rak raeg, or “first love”. But whatever it is called in Thai, the dahlia has many good qualities that are difficult to ignore, and modern plant lovers must count their blessings that they do not have to spend a fortune to obtain it. It is easy to grow, whether from tubers or from seed, with failures usually occurring from over attention rather than neglect.
This does not mean that the plant will thrive on bad treatment but too much water or shade will surely kill it. It prefers a sunny place and therefore should not be planted in the shade or near big trees. Well-drained loamy soil mixed with manure or compost is also necessary to keep it thriving, and given ordinary attention will bloom in abundance and its lovely flowers can be enjoyed for weeks.
Plants sown from seeds usually bloom within three or four months after replanting the seedlings. Sow seeds in a seed box or a big shallow pot, using a combination of coarse sand, finely shredded coconut fibre and compost. Water sparingly. When the seedlings are 6cm high, transplant them in individual pots and increase the water supply just to ensure that the soil is sufficiently moist. When the plants are 30cm high, apply a teaspoonful of complete fertiliser around the base of each plant, rake it in lightly and then water thoroughly.
Carefully stake the plants from the very beginning to prevent them from breaking, and thin out excessive growth of foliage by pinching out the third pair of leaves from the bud. Some varieties produce too many flower buds, in which case pinch out the first two side shoots if a large flower is desired.
Remove all withered flowers as quickly as possible to give way to new ones. If blooms are required for the flower vase, pick these in the cool of the evening and dip the ends of the stem in boiling water — but make sure to wrap the blooms in newspaper to keep them from the rising steam — then plunge the stems up to the neck in cold water. By doing this, the flowers will keep longer in the vase.
The plants develop tubers. When the plants have completely died out, lift the stumps with the clumps of tubers from the pots and store these in a shaded place. The soil that adheres to them should be enough to keep them in good condition until they send out small “eyes” or shoots from around the stump of the old stem. The clump can then be divided by carefully cutting off each tuber with a sharp knife, making sure that each piece carries a shoot or an eye. Allow the cut surface to heal, then pot the tuber with the shoot up, beginning another cycle.