Problems With Wave Petunias

• Wave petunias create a mass of cascading color. Jupiterimages/liquidlibrary/Getty Images

  Wave petunias create a cascade of brilliant color when hung from baskets, added to window boxes or planted atop rock walls and raised beds. These non-stop bloomers begin blooming in late spring and continue until they are killed by frost in the fall. Relatively care free, many gardeners turn to petunias to brighten the yard and add delicate fragrance.

Insects

• Petunias typically are pest free but may suffer from the effects of an aphid or white fly infestation, according to the Alabama Cooperative Extension System. They are known to attract slugs and ear wigs. Control consists of applying insecticide when necessary but may be attained by hand picking and sound cultural practices. Remove dead foliage, avoid wet foliage late in the day and check plants often for signs of insect pests. Greg Stack, a University of Illinois Extension educator, recommends applying carbaryl every seven to 10 days as needed to kill insect pests.

Disease

• Damping off and grey mold may result from poor cultural conditions, such as overwatering or poor drainage. Clemson University Extension also cites petal blight as a result of poor growing conditions. Prevention includes proper maintenance, deadheading and attention to removing old foliage. Petunias are prone to mold when humidity levels remain high or foliage remains wet at night.

Dried Foliage

• Wave petunias grow rapidly and are heavy feeders. Failure to provide adequate water results in wilting. Without quick action, foliage may shrivel and dry, leaving the plant with no means to produce new food. Check your petunias daily, especially in hot dry weather. Water when the soil feels dry to the touch.

Mineral Deficiences

• Petunias are susceptible to a boron deficiency that may result from a pH above 6.5 or from lack of boron in the potting media. A boron deficiency manifests with distorted or mottled leaves that may appear stiff. An iron deficiency, characterized by yellowing of the leaves while the veins remain green, may result from a pH above 6.5. Treatment consists of maintaining a proper pH between 5.0 and 6.0, and providing boron and iron supplements.