You do need at least 18 inches of loose, clot free soil beneath the carrots. The seeds themselves are spread on top of the soil and covered with a light covering of dirt. one trick is to mix radish seeds with the carrot seeds. Radishes mature faster than carrots. Removing the ripe radishes, effectively thins out the carrot bed. By the way, if you have heavy clay soil, expect short, thick carrots.
You do need at least 18 inches of loose, clot free soil beneath the carrots. The seeds themselves are spread on top of the soil and covered with a light covering of dirt. one trick is to mix radish seeds with the carrot seeds. Radishes mature faster than carrots. Removing the ripe radishes, effectively thins out the carrot bed. By the way, if you have heavy clay soil, expect short, thick carrots.