Carrots need to grow in finely textured, well-drained soil so time spent preparing the seed bed is time well spent. If the soil has been weedy in past years, try the stale seedbed technique. First, prepare the area to be seeded, then water well before planting any crops. Wait a week or two for weed seeds to germinate, then skim them off without disturbing the soil deeply, which could bring more weed seeds to the surface.
Plant carrot seed as soon as the threat of a hard freeze has passed. Many growers like to add a small percentage of radish seeds in with the carrot seeds because radish will germinate first and loosen the soil. Because weed control is critical to carrot success, we recommend sowing seeds in a straight line and marking it with a label so you can differentiate weed from carrot seedlings. Space rows 18-24 inches apart. Keep well watered and weeded. Carrots can take up to 3 weeks to germinate.
When the ferny foliage of carrots is 1-2 inches tall, thin to 2 inches apart by snipping off the excess plants at the soil line so as not to disturb the roots. Mulch the carrot bed to keep down weeds and prevent sun scald on the carrot shoulders.
Harvest when the top of the root is about an inch wide. For fall, leave roots in the ground through a few frosts for best flavor.