48 DAYS Bright green leaves, tender and sweet at all stages. Black-Seeded Simpson has been a favorite leaf lettuce for generations of gardeners. Withstands heat, drought and is slow to bolt. Make planting Black-Seeded Simpson a cinch with seed tape! Seeds are encased in biodegradable paper that protects the seeds during germination and dissolves in the course of watering. Simply cut the tape to the desired length, place in the garden or in one of our Grow Tub™ containers and water—no worries about over- or under-seeding!