I’ve heard people say that they have trouble getting full-sized carrots, but I’ll say I’ve never had that problem. I grow mine in raised beds, and I make every effort not to step in the beds and compact the soil. My soil is high in nitrogen, which may help. The variety grown may make a difference as well. The large ones I get are the variety “imperator.” Nine-inch carrots that are two inches thick are not unusual. The hardest part is getting them started from seed. My experience so far is that their flavor, however, decays a bit when you let them get too big – it’s as if the flavor just gets more spread out over the carrot. The smell, however, is really divine and can be savored like a perfume. And they can be stored in the ground until you need them – just go into the garden and pull one up.