Petunias, a colorful herbaceous perennial, offers virtually nonstop blooming during the summer with rapid spread. Normally grown as an annual, the plant produces single, double or ruffled blossoms in shades of pink, purple, lavender, white, red or yellow. Many blossoms are multicolored in shades of purple and white or red and white. The plant grows only 6 to 8 inches high, which makes it an ideal border addition. Petunias also flourish in containers and baskets. A few varieties of petunias also offer a soft, subtle fragrance.
Choose a sunny location. Petunias require at least six to seven hours of sunlight per day.
Work aged manure and peat moss into the soil to a depth of 10 inches. The soil should feel crumbly to the touch.
Plant young petunias early in the spring after all danger of frost has passed. Planting early helps the plant build a strong root system which will aid it in blossom production. Strong roots also help the petunia to withstand the hot summer.
Space each petunia plant 1 to 2 feet apart to allow the plants to have air circulation and give them adequate room to spread. Plant at the same depth the plant was in its nursery pot. Choose a location that offers well draining soil. The petunia does not tolerate water-logged soil.
Apply 2 to 3 inches of mulch, such as bark chips or peat moss, around the plants' base. The mulch will help keep the petunias' roots cool in the summer and help the soil stay moist.
Water petunias in the morning so the foliage dries out before nightfall. Allow the soil to dry out between waterings.
Fertilize the petunia every two weeks using a water-soluble general purpose fertilizer such as a 10-10-10 or 12-12-12. Apply according to the directions on the label.
Pluck away dead flower heads as they appear. Removing the spent flowers helps the plants overall appearance and also encourages it to produce more blossoms.