It attains a height of 45 to 55 cm ( 18 to 22 in ) , and a spread of 70 to 80 cm ( 28 to 31 in ) , with 80 to 90 cm ( 31 to 35 in ) rows that seldom cover the ground .
It attains a height of 18 to 22 inches , and a spread of 28 to 30 inches , with 33 to 36 inch rows that seldom cover the ground .