The perfect way to add new and interesting plants to your garden is by planting seeds during the winter. A small packet of flower or vegetable seeds yields a compete tray of seedlings for the same price that you would pay for just a few retail plant starts. Another advantage of starting your garden with seeds is that in a few short weeks you'll witness one of the most exciting times for gardeners, the birth of new seedlings as they emerge from the soil.
Although some seedlings are ready for transplanting earlier than others are, a rule of thumb is to start most annual seeds indoors six to eight weeks before you expect the last frost in your area. Seeds started too early tend to get leggy with weaker stems. Those started too late won't be vigorous enough to transplant when you're ready to garden outdoors.
Seedlings are very susceptible to molds and other fungus, both of which are usually caused by over watering or poor drainage. Use sterile potting soil when planting seedlings to help ensure that spores and pathogens won't affect your planting. Also, be sure to keep the potting mixture moist but not wet. Fertilize your seedlings after the first set of leaves emerges, using a water-soluble fertilizer.
Seedlings require intense light, and while natural sunlight is best, it is often difficult to provide an adequate amount of sunlight during the short, late-winter days. However, seedlings tolerate artificial light in addition to a good dose of natural sunlight when it's available. Seedlings typically thrive with a minimum of 14 hours of light each day. Because young plants have a tendency to lean towards the light if you're growing them in a window, don't forget to turn your seedlings periodically to keep them standing straight. Of course, before you can start seedlings, you'll need to find seeds to start!