Dahlias are native to the high plains of Mexico and other parts of Central America. They were cultivated by the Aztecs in pre-Cortez times. They were introduced to Europe by the Spanish in 1784. They were first first grown in the Botanical Gardens in Madrid. Abbe Cavanille named the new plants Dahlias in honour of Andreas Dahl a Swedish naturalist and student of Carl Linnaeus. Littel Robert is purplish red against a paler background so one sees the shapes of the petals as well as the ball that they form. All these make great cut flower, not dominating the arrangement but adding to it.
Tender. Store tubers dry until March, then pot up and grow with warmth to plant out in late May. They need planting in a sunny situation with good compost below them and regular dead heading in the late summer to encorage repeat flowering. Growing them initially as potted plants early in the season will give you a head start. In the winter they may need to be lifted and kept frost free, depending on the conditions.