Dahlia Timeline
John Wedgewood grows Dahlia plants for the first time.
Richard Salisbury (1761 – 1829) receives Dahlia seed from Lady Holland’s garden.
John Wedgewood (1766 – 1844) founder of the Royal Horticultural Society, grows Dahlia plants for the first time.
Cultivation Methods are Documented
Richard Salisbury writes for the Horticultural Society (Later the Royal Horticultural Society) on the different species of Dahlia and the best method of cultivation in Great Britain.
John Wedgewood, founder of the R.H.S, writes about his achievements at growing Dahlias in Staffordshire for the Horticultural Society (Later the R.H.S).
First Exhibition in Scotland
First recorded exhibiting of dahlias in Scotland, receiving Silver Medal.
Dahlia juarezii Named

Van der Berg catalogued a new dahlia for sale, calling it Dahlia juarezii to honor Mexican President Benito Pablo Juarez, who had died the year before.
“Revision of the Genus Dahlia Asteraceae: Heliantheae-Coreopsidinae” Published
Paul D Sørensen, published in Rhodora, “Revision of the Genus Dahlia Asteraceae: Heliantheae-Coreopsidinae”.
Six Species Added

Jen P.Hjerting, Paul Sørensen & Dayle Saar jointly travel through Mexico collecting species Dahlias and add six more species to the list, Dahlia campanulata, Dahlia neglecta, Dahlia hjertingii, Dahlia cuspidata, Dahlia spectabillis, Dahlia parvibracteata.
See Species Dahlias.