Gardeners who live in cold climates have shorter growing seasons. While Southern gardeners are planting their vegetable seeds and seedlings outdoors during February or March, gardeners in the North must wait until the ground thaws out during March through June. If you live in a locale where the winters are harsh, you can start your vegetable plants with an indoor system. Indoor seed starting systems enable every gardener to start their seeds indoors and lengthen their growing seasons. According to online resource Edible Container Gardening, it just takes a few items to create your own indoor growing system.
Fill the containers with sterile potting mix. Sterile potting mix is treated to eliminate the risk of bacterial or fungal infection. Do not fill the container all the way to the rim, to avoid losing some of the potting mix to overflow when you water.
Follow the directions on each of the seed packets. Seeds have different planting needs, and shouldn't all be planted in the same way. Plant three seeds in each of the containers. Not all seeds in a packet are viable. Plant more than one to ensure you'll have at least one sprout per container.
Water the seeds with a plant misting spray bottle. Edible Container Gardening advises this method to avoid overwatering, as the seeds are close to the surface of the soil. The misting bottle gives you more control over how much water is used on the soil and seeds.
Place the containers near a light source. The seeds need at least eight hours of sunlight per day. A window with unshaded southern exposure is ideal. If you don't have a sunny window, use a grow light suspended 6 inches above the containers. For best results, use chain links to suspend the lights over the containers, and adjust its height as the seeds sprout and grow.
Place the containers on a heating pad set on the lowest setting if the indoor temperatures are colder than 65 degrees F. Seeds do not germinate or develop properly if temperatures are too cold. Extremely cold temperatures shock the seeds and make them remain in dormancy.
Pluck the weaker seedlings from each container, and leave just one per container. The extra seeds are planted in case some of them do not sprout. If you leave all of the seedlings to develop, the root systems will be crowded and the seedlings will compete for light.
Transplant the seedlings into their final destinations (larger containers or directly into the ground) when the soil thaws and outdoor temperatures are warm enough to support the plants' development.