Florence fennel or finocchio is grown primarily for its bulbous base and leaf stalks which are used as vegetables. Fennel is a stocky plant which can grow to 24 inches tall and looks something like celery with fleshy stalks and feathery leaves. Culture: Rich, well-drained soil, regularly irrigated, and cool temperatures produce top quality bulbs. Plants grow best and the flavors are superior when daytime air temperatures are 60–70°F. Start to blanch the lower stems when the bulb is the size of an egg by hilling up soil around the bulb. Harvest: You can harvest fennel leaves anytime during the growing season – the more you trim it, the bushier it will become, leading to more and bigger harvests for you. Be sure not to trim more than a third of the plant when you harvest.