Root vegetables are often mistaken as incompatible with container gardening, but for the urban gardener with limited land a container might be the best way to yield an abundant crop of carrots. Growing in the ground makes your root crops more susceptible to pests and with a crop as picky as a carrot is about the soil it prefers to grow in we might as well make one ideal habitat for the carrots and not fuss over preparing and protecting an entire plot.
Any container of about 10 inches deep can be prepared with loose, sandy soil and densely planted. Broadcast the carrot seeds over the soil and cover by sprinkling a thin layer of soil over top. Soak thoroughly and then water daily. As the greens begin to develop their bushy fronds, thin them to about 1 cm apart. Thin again at the 10 week mark leaving at least an inch between plants to finish developing. The thinned greens are delicious and can be added to salads or used like parsley as a brightening garnish.
Carrots are very cold tolerant so plant early, as soon as the ground thaws, and grow multiple crops through summer and into fall. And if you like garlic, a few cloves in the pot will make great companions for your carrots. Any allium (onions, garlic, shallots, etc.) ward off slugs, worms, and carrot fly that make harvesting beautiful carrots a chore. Simply plant a few cloves from your store-bought garlic, roots down, to grow more heads and keep your carrots healthy.
If you enjoy the carrot greens, keep them handy in the kitchen by placing your scrap carrot tops in a shallow dish of water and place them in a sunny window. Even if cut down to nubs, the greens will continue to grow. When the tops begin to develop new roots, transfer them to a small pot of soil.