Preseeding gives you a head start on the growing season. It is especially useful if you live in a northerly location with a short growing season. Annual flowers can be preseeded and ready to plant, with 4 or 5 inches of growth, after the last frost of the season. Preseeded plants allows you to harvest earlier, or even grow vegetable choices not ordinarily available in your location.
Collect reused food cartons--such as Jello, pudding, yogurt or cottage cheese containers--to use as seeding pots. Poke several holes in the bottom for excess water drainage. Use a nail or awl for this purpose. Peat pots and seed trays are also available at garden centers and nurseries.
Pour potting soil into the seeding containers, leaving ½ to ¾ inch clear at the top. Wet the soil with a couple sprays of water. Stir to moisten all the soil in each container.
Read the planting depth directions. This will be found on the back of the seed packet. Different seeds need different planting depths. Generally, the smaller the seed the more shallow it is planted.
Make a hole, with the end of a pencil, to the depth needed for the type of seed you are planting. Place a seed in the hole. Smooth soil over the hole. Repeat this process for each seeding container.
Gather all the containers and put them on a tray. Put the tray near a window that gets six to eight hours of sun each day.
Give each container one squirt of water. The soil must be kept moist, but not soggy, for the seeds to germinate. Place a sheet of plastic wrap on top of the tray, but don't seal it as the seeds need some airflow. The plastic wrap will keep the soil warm.
Check the soil often. When it appears to dry, give each container of soil a squirt of water. Remove the plastic wrap when you see green sprouts popping through the soil. This is called seed germination. Continue to water the soil when it becomes dry.
Transplant the seedlings outdoors, when they are about 4 or 5 inches tall and the last threat of frost of the season has passed.