Care of petunias includes regular watering and as much sunlight as possible to promote multiple blooms. Spreading ground cover petunias are pickiest about water; weekly waterings should be included in the care of petunias. While petunias will grow in a partially shaded location, a fuller and more abundant bloom is produced in full sun. Soil prepared before planting petunias should have well-composted organic matter worked in. Care of petunias will include regular fertilization with a balanced, water soluble fertilizer designed for blooming plants. As they are heavy feeders, petunias care will also include weekly feedings. Proper light, water, and fertilization when caring for petunias will ensure a long season of beautiful blooms.