The Germination of a Petunia

Container

• Petunias seeds can be germinated in a variety of containers. Peat pots, plastic cell packs, individual plastic pots or practically any other small container can be used. Drainage holes are a must for success, as they allow excess water to escape so that the roots of developing seedlings don't rot. The sterility of the container is also an important factor; clean reusable containers with a bleach water solution before use. Sterilization isn't necessary for peat containers or those that have never been used.

Growing Medium

• For best results, sow petunia seeds in a sterile, fine-grade medium. This prevents compaction and allows the tender seedlings to sprout easily. Milled sphagnum moss or quality potting soil make good choices. Garden soil should be avoided because it is likely to contain diseases and is often too heavy for effective germination. Moisten the chosen media just before sowing the petunia seeds.

Sowing Seeds

• Petunia seeds are minuscule and difficult to sow without covering too deeply. Press the seeds lightly into the moistened growing medium rather than sprinkling soil on top. A piece of clear plastic stretched over the surface of the container seals in moisture, making it unnecessary to add water again until the seedlings emerge. Move the container to a brightly lit location with temperatures of approximately 70 degrees Fahrenheit. Remove the plastic as soon as petunia seedlings appear.

Moisture and Light

• Occasional watering is necessary once the plastic is removed. Keep the soil barely moist, but not wet, as this may lead to root rot. Daytime temperatures of 65 degrees Fahrenheit are ideal, with nighttime temperatures that that dip no lower than 55 degrees Fahrenheit. A full sun location is necessary for rapid healthy growth. If exposure to plentiful natural light isn't available, place the seedlings under fluorescent lights for 14 to 16 hours each day.

Transplanting

• Young petunia plants need exposure to outdoor weather for two weeks before being moved outdoors. Place the containers in a shady location each day and bring them back inside before nightfall. When the plants have three true leaves, which form after the initial seed leaf emerges, they are ready for transplanting. A site that receives full sun and has well-drained soil is best.