The Bonnie Plants 19.3 oz. Green Romaine Lettuce Plants comes with compact, dark green rosettes of tall, upright, slightly curly leaves with white hearts and a crisp, sweet flavor. Slow to bolt. These plants grow best in full sun but will tolerate partial shade and even appreciates it in hot climates. Lettuce matures 21 days after planting. You must water these plants once the soil becomes dry.