Dahlia - Double Dahlias

Double Dahlias

That same year, several new species were reported with red, purple, lilac, and pale yellow coloring, and the first true double flower was produced in Belgium. One of the more popular concepts of dahlia history, and the basis for many different interpretations and confusion, is that all the original discoveries were single flowered types, which, through hybridization and selective breeding, produced double forms. Many of the species of dahlias then, and now, have single flowered blooms. D. coccinea, the third dahlia to bloom in Europe, was a single. But two of the three drawings of dahlias by Domenguez, made in Mexico between 1570–77, showed definite characteristics of doubling. In the early days of the dahlia in Europe, the word "double" simply designated flowers with more than one row of petals. The greatest effort was now directed to developing improved types of double dahlias.

During the years 1805 to 1810 several people claimed to have produced a double dahlia. In 1805 Henry C. Andrews made a drawing of such a plant in the collection of Lady Holland, grown from seedlings sent that year from Madrid. Like other doubles of the time it did not resemble the doubles of today. The first modern double, or full double, appeared in Belgium; M. Donckelaar, Director of the Botanic Garden at Louvain, selected plants for that characteristic, and within a few years secured three fully double forms. By 1826 double varieties were being grown almost exclusively, and there was very little interest in the single forms. Up to this time all the so-called double dahlias had been purple, or tinged with purple, and it was doubted if a variety untinged with that color was obtainable.

In 1843, scented single forms of dahlias were first reported in Neu Verbass, Austria. D. crocea, a fragrant variety grown from one of the Humbolt seeds, was probably interbred with the single D. coccinea. A new scented species would not be introduced until the next century when the D. coronata was brought from Mexico to Germany in 1907.

The exact date the dahlia was introduced in the United States is unknown. In 1840 Thomas Bridgeman, supplied a catalog of "all the choicest varieties available." He stated that a list and description of about 100 choice seedlings of 1838 and 1839, which had been purchased in England and grown in the garden of Mr. G. C. Thornburn of Astoria, N.Y. had been furnished to him by that gentleman and would be offered for sale in 1840. To this list he added about two hundred fifty varieties, "most of which he had under cultivation in his own garden."