Thomas Edison

Introduced in 1929 and, per a 1939 L.L. Olds catalog quoted by Old House Gardens, named for the famous Electrical Wizard with his approval, this is the rare dahlia with a celebrity endorsement from the subject himself. Edison died in 1931; his dahlia never did. It is still widely called the best purple dinnerplate on the market, an astonishing run against ninety-plus years of challengers. The breeding credit is murkier than the fame, with sources splitting between a Dutch origin and the Dahliadel operation in the United States. Either way it remains the purple to beat, and the easiest legend on this list to actually buy.

Thomas Edison is a formal decorative with 6 to 8 inch blooms on 3 to 4 foot plants per Old House Gardens, dinnerplate presence without the most extreme staking demands of the true giants. Still, support it well; those velvet heads hold rain. Bear Creek notes florists love its straight, elegant stems, and they cut long if you disbud with discipline. Deep purples can scorch at the petal tips in brutal sun, so afternoon shade in hot climates keeps the velvet pristine. Nearly a century of garden survival means it tolerates imperfect treatment better than most. Diva delivers a related iridescent purple in a smaller, more productive package if row space is tight.