Fennel Mantovano. One of the larger fennels, this one has a round very white bulb. Earlier than most fennels. Very sweet with a nice texture. 75-85 Days. Does best in fall. Best grown from direct seeding (2-3 seeds every six to eight inches, thin to one), although you can transplant if you are careful not to disturb the roots. Provide a constant source of moisture. Make sure to harvest some small ones; they are even sweeter and more tender. 7 gram packet. Approximately 300 seeds per gram.