Petunias are versatile annuals. They can be used for color masses, borders, containers, hanging baskets or as a seasonal groundcover.

Petunias should be planted in full sunlight. They will become spindly and have few flowers if grown in shade.

Petunias grow well in most soils. Best growth occurs in well-drained, light soil of medium fertility. If the soil or the area is poorly drained, you can build raised beds to grow good petunias. They prefer soil with a pH of 6.0 to 7.0.

If you grow petunias from seed, start them eight to 10 weeks before planting in beds. The very fine dustlike seed of petunias require light for germination.

Purchase healthy young petunias that are short and compact. Leggy, thin plants are slow to adjust to outdoor conditions. Young plants not yet in bloom often settle in faster.

Plant petunias as soon as the danger of frost is past in the spring. Plants should be hardened off before planting into exposed beds. Place the plants in a protected place such as a cold frame or sheltered area close to buildings to adjust them to outdoor conditions. Keep them well-watered during this period.

Pinch off the top inch before planting to encourage good branching. For good ground cover, space petunias 12 to 18 inches apart.

Plants need at least 1 to 2 inches of water every seven to 10 days once established. Avoid frequent light watering that encourages shallow rooting. Fertilize petunias monthly with a balanced fertilizer to support their rapid growth and heavy blooming.

If plants become leggy or stop flowering, prune the shoots back to about half their length. You can cut back to within a few inches of the base if needed, but do not remove all their leaves. Fertilize with a liquid fertilizer. Water well to force out new growth and flowers.

Large-flowered and double petunias will need to be deadheaded (removal of old and dying flowers) to improve appearance and bloom production. Many of the smaller-flowered cultivars are self-cleaning.

Petunias often reseed in the garden, but will not return true to type. They usually revert to a mix of small white, lavender and rose flowers.