Petunias are one of the more popular flowers to start from seeds. They take very little to start and sprout quickly compared to other flowers. If they are well taken care of, you'll have bright, cheerful flowers blooming all summer.
When prepping to plant petunias, it's important to choose an area with a lot of light. Soil used needs to drain well; add compost to help fertilize the soil to give the seeds a good start. Because it takes several weeks for petunias to grow to the size needed for transplanting, it's best to start indoor seeds four to six weeks before the last frost.
One of the challenges of planting petunia seeds is the small size of the seeds. When planting, sprinkle the seeds over the intended area and pat the seeds down to get them into the soil. Water the area with a fine mist so as to not over-water. Cover the area with a clear lid or plastic wrap to keep moisture in.
Petunia seeds germinate in as little as three to four days given the right conditions. Seedlings sprout within a week of planting. They are ready to be transplanted about 14 to 21 days after sprouting. You can tell they are ready to be moved when they reach the "two leaf stage."