available. In India, a large number of cultivars are available, especially in Andhra Pradesh, Karnataka, Tamil Nadu, and Kerala. Some ornamentals with very beautiful foliage also belong to this species. There are many cultivars in Southeast Asia classified according to leaf color and shape.
Vegetable amaranths need a long warm growing season, and are suited only to the warm-temperate and hotter zones of the earth. If grown in cooler climates they tend to be tough and poor in quality.
Rainfall The crop thrives in areas receiving 3,000 mm of annual rainfall. As it is mostly grown in small plots beside the house, it is frequently watered by hand. Without irrigation it needs an average of at least 8 mm per day of rainfall during its whole season.
Altitude Areas with elevations below 800m are said to be most suitable for cultivation, but the crop can be grown in higher areas. Amaranthus cruentus, for example, thrives in altitudes up to 2,000 m.
Low Temperature All species are very sensitive to cold weather. Plant growth ceases altogether at about 8°C.
High Temperature Most species are tolerant of high temperatures and thrive within a temperature range of 22-40°C. The plants establish best when soil temperatures exceed 15°C. Optimum germination temperature varies between 16°C and 35°C.
Soil Although most amaranths tolerate a wide range of substrates, a light, sandy, well-drained, and fertile loam is desirable. Soils with a high organic content and with adequate nutrient reserves produce the best yields. Optimum pH range is 5.5-7.5 but some cultivars tolerate more alkaline conditions.