Sowing

• Vegetable seeds can be sown either in artificial containers in a soil mix indoors, or directly into the soil outside. One good reason for sowing seeds indoors is to start plants early in the season, when the danger of frost is too great. This allows plants that take time to mature and that need a fairly lengthy, warm growing season to get a head start. Tomatoes and peppers are good examples of seeds that are often started indoors.
  
  

Water

• Vegetables, of course, need water. Moisture is what stimulates the seeds to germinate. And once the root and shoot have formed, a new seedling needs adequate water on a continuous basis to grow and develop. Oftentimes, water is supplied artificially in an outdoor garden when rainfall is insufficient. Indoors, seeds are often sown in sections of plastic cells similar to egg cartons. The plastic cells have perforated bottoms and sit within a watertight tray. Water can then be added to the tray, and the soil mix will soak it up from the bottom through the perforations.
  
  

Light

• Although seeds generally do not need light in order to germinate, once they've sprouted, light is essential. Inadequate light will cause the vegetable seedlings to be pale and spindly, and this will interfere with their growth and development. Indoors, light can be provided through a sunny window, a sunroom or similar setting, and can be supplemented with artificial light. The artificial light should produce a balanced spectrum that approximates natural sunlight as closely as possible.
  
  

Nutrients

• Just as seeds don't necessarily need light to germinate, the seeds and new seedlings generally don't require much in the way of nutrients. Once they've become established and begin to grow and develop, however, the young plants need nutrients in increasing amounts. When sown outdoors in a garden setting, if the garden soil is in good condition and reasonably fertile, the young sprouts should get off to a good start. Indoors, fertilizers can be added to the seed starter mix to help the sprouts along.
  
  

Temperature

• As with any biological process, plant growth and development are temperature-dependent. Seeds sown in very cold soil may show very poor germination or may not germinate at all. Once the seeds sprout, they'll continue to need warmth and--especially in colder regions--protection from potential frosts.