Jiffy pellets are made from pure compressed sphagnum peat moss with mesh to hold their shape. When watered, they expand to seven times their size and become a complete growing unit! The expanded pellets grow to 1 1/2" in diameter and 1 1/8" deep. Seeds may be started directly in the expanded pellets and eventually the entire system may be planted directly into the garden. Jiffy 7"s are a convenient way to start flower and vegetable seeds!