ANNUAL BLUEGRASS, Poo annua L. 1, entire plant; 2, spikeIet; 3, seed. Annual in the North Central states. Grows well in cool weather but is not winter hardy. Roots shallow, easily pulled from the soil. Stems 1 to 12 inches (2.5 to 30 cm) tall, often decumbent at base, sometimes rooting at lower joints. Leaves a soft, light green. Panicles very small in clipped lawns; plants flower during the entire growing season. Prevalent in lawns and gardens, particularly those with moist, rich soils.