Growing seedlings indoors has many advantages. It is possible to try plant varieties that are rare or have only recently been introduced. For species with a vegetative cycle that is too long for our climate, such as the tomato, eggplant and pepper, growing the seedlings indoors produces a quicker and much larger yield. Moreover, many annually flowering plants such as petunias, begonias and celosias must be sown indoors.

The most important factors in successful growing are adequate lighting, appropriate temperature, high humidity and a light and sound subsoil. Even with the best seeds, results can be disappointing if these basic criteria are not met.