Jonathan Green 7 lb. Fast Grow Grass Seed Mixture. This fast-growing grass seed mixture provides a hardy turf quickly in both sun and shade. It is the perfect seed mixture for areas where the fastest results are required, and it germinates in just 7 to 14 days. This mixture is ideal for full sun to medium shaded areas and covers up to 3500 square feet. It contains a blend of annual ryegrass and Kentucky bluegrass, which helps to create a thick, healthy lawn.