If you have planted seeds indoors and see them sprouting, you have accomplished stage one of development! You may wonder which steps to take next. Correct light, moisture and nutrition are necessary for proper development of the seedlings. Some instructions are included on the seed packet.
Provide the light suggested for your particular seeds. Young seedlings may require sun for part of the day and many require increased sunlight as they grow. Take the tomato, for example. Following its first stage of development; the roots; sunlight should be increased. After four or more leaves have developed stage two is complete, and again a little more sunlight is needed.
If your plants are leaning or stretching to get sunlight, this indicates light should be increased. Stages three and four of the tomato’s development will require progressively more light. The plant should stand straight. If it is receiving proper sunlight and leaning, it may be time for the tomato stake or tie up. Different plants require different light levels.
Water and Fertilization
Feeding your indoor seedlings is an important part of the growing process. Once seeds have germinated they may benefit from a weak mixture of liquid fertilizer. Often this is applied with every other irrigation after the cotyledon (sprout) peeks through the surface. A nitrogen-based brand of 14-0-14 that you mix yourself is preferable. Keep in mind that any tomato which is nitrogen deprived during any stage of development will not be an optimum producer.
Fertilizer types and amounts may vary from plant to plant. Ask a professional at your local garden center or look the plant up online for specifics.
As with sunlight, the strength of the fertilizer should be increased during each stage with most seedlings. More water will be required at each irrigation, but irrigation will often become less frequent. Let water come to room temperature before using it on tender seedlings (usually 24 hours). Temperature of media and water can make or break your crop strategy.
Once the seedlings appear to be outgrowing their container, it is time to transplant. If your plants will go into outdoor beds, get them gradually used to the outdoors. Start with a few sunny hours and increase outdoor time.
Growing plants from seeds can be a rewarding and money-saving adventure!
http://www.pallensmith.com/articles/readers-choice-plants-you-can-grow-from-seeds accessed 02-19-2010
Ball Redbook, Volume 2