Temperature - the temperature range in which plants grow
1) tender or chilling sensitive: 32 to 45 oF (0 to 7 oC)
2) semi-hardy plants: 15 to 29 oF (-9 to -2 oC)
plants: less than 0 oF (-18 oC)
1) in southern U.S.: grow as fall-winter crops.
2) in northern U.S.: grow in late spring, summer, early fall
b) warm season plants: grow best at 78-90 oF (24-32 oC)
1) in southern U.S.: grow in late spring and summer, early fall
in northern U.S.: grow in summer, but for some warm season crops the growing
b) survival: 130 oF (54 oC), most species.