Seeds contain the genetic makeup of a plant. Beneath the tough seed coat lays an immature plant---an embryo---that contains all the parts of a mature plant from tiny roots to leaves. It also contains endosperm to feed the embryo from the time it germinates to the time it is able to make its own food. Germination occurs when the seed absorbs moisture and breaks through the seed coat. For some plants, germination occurs in as few as three days, while others require three weeks or more. How you speed up the process depends on the type of seed.
Scarify tough seed coats like morning glory before planting. Rub the seed coat with fine sandpaper or a fingernail file to thin the surface of the seed coat. This allows the seed to take in moisture and allows the sprout to break through the seed coat with ease. Check the back of seed packets to determine if seeds need to be scarified.
Soak legumes, as well as other dense, hard seeds such as corn, in lukewarm water overnight to speed germination. Place in a bowl that holds twice the volume of the seeds and fill with water. Seeds absorb moisture and swell to nearly double in size. Plant as directed on the packet.
Moisten a folded piece of paper towel. Layer fine seeds or flat seeds, such as melon and cucumbers, on the towel and fold to cover. Place the moist towel and seeds in a plastic food storage bag and set in a warm area. Check seeds daily. Remove and plant once sprouts appear.