- This Nantes-style carrot has been cultivated for generations because of its uniform orange carrots with indistinct cores.
p>Amsterdam Carrot Seeds. AKA: Amsterdam Forcing 2. 50 to 70 days. Non-GMO, Heirloom (Open Pollinated). Daucus carota. A Nantes-style carrot, the Amsterdam is a European heirloom cultivated for generations for reliable and uniform 4-6" long bright orange carrots with indistinct cores. Prior to the Dutch influence of the 16th century, the world's carrot crop had once been all purple, whereas orange was the mutant variable that Dutch growers sought to isolate as a separate cultivar. Biennial but commonly grown as an annual in the USA.