3 to 5 days. One of the most nutritious vegetables in the world. Compared to mature broccoli, broccoli sprouts have 50 TIMES AS MUCH SULFURAPHANE, a naturally-occurring plant chemical that serves as an anti-oxidant. Do yourself a favor -- and satisfy the desire for crunchy, delicious fresh veggies! -- by growing this super-quick sprout! Packet is 1/2 ounce, which is at least 3,000 seeds.