Care

• Unlike traditional petunias, wave petunias require very little care. The flowers don't need to be deadheaded, and the plants never need pinching back. Once the roots are established, they are heat tolerant and do well in full sun. Start wave petunias early for a well-established root system. Wave petunias need at least six hours of sun to thrive. Gardeners should not let their wave petunias dry out between watering. Wave petunias need lots of water, but should be kept in well drained soil. The plants don't need to be mulched, since the flowering parts serve as a ground cover to suppress weeds and hold water into the soil. Plants should be placed in the soil at the same depth as the peat pot that the plant came in. Wave petunias should be spaced approximately 12 to 24 inches apart. For containers and hanging baskets, three plants in a 10- to 12-inch container.
  
  

Feed

• Wave petunias perform best if they are regularly fertilized. These plants should not be placed in the same plot of soil for more than one year at a time. When used in containers, the soil should be changed yearly. Although the best fertilizer for wave petunias is a liquid fertilizer added to the petunias' water every 10 to 14 days, a slow-release fertilizer placed in the soil also works well. Petunias that do not receive regular fertilizer might exhibit yellowing leaves.
  
  

Cutting Back

• In late summer, wave petunias can start to look leggy as their stems grow long and spindly. This is more of a problem with petunias that are grown in containers than it is for ground cover wave petunias. If your container-grown wave petunias begin to look leggy, you can revive them by cutting them back. One method of cutting petunias back involves cutting every stem back to the first four leaves. Another includes cutting every other stem back so that you still have some long, trailing stems. Finally, some gardeners buy twice as many petunias as they would normally, and keep some cut back until midseason, when they will let them grow. These petunias fill in the containers just as other petunias begin to look too leggy.