|'Thumbelina' is a baby carrot which matures extremely early. It is globe-shaped like 'Parmex', but will also tolerate heavy soil. Loose, well-drained soil, free from clods and stones are a must for carrots. If your soil is less than ideal, plant only short rooted varieties. A hardy biennial grown as an annual, carrot tops are a rosette of fern-like foliage growing from a swollen tap root. A cool weather crop that is easily grown with few disease or pest problems, they should be planted in early spring with successive crops being planted every 2 to 3 weeks until early summer for a continuous crop. Start 2 to 3 weeks after the last average frost date. They may be cold tolerant, but seeds take forever to germinate in raw weather. Carrots should be planted in full sun, but will tolerate partial shade. Prior to planting, work a low nitrogen fertilizer such as 5-10-10 into the soil. Make sure soil is loose and rock free.