Purple wave is the original color in this group of seed-propagated, spreading petunias at the Hammond Research Station. (Photo by Igor Kamalov)

The Tidal Wave petunias are aggressive growers. Cherry is a popular color and can reach hieghts of 2-3 feet with an equal spread. (Photo by Igor Kamalov)

Bicolor petunias are being introduced. This is Easy Wave Burgundy Star being grown at the Hammond Research Station. (Photo by Igor Kamalov)

News Release Distributed 02/11/11

By LSU AgCenter Horticulturists Dan Gill, Kyle Huffstickler and Allen Owings

Petunias are one of the most popular flowers in Louisiana. They can be planted in fall for cool-season color or planted in late winter or early spring for warm-season color.

Common questions pertaining to landscape performance of petunias include: What can be done to extend their flowering time in the landscape? Are there variety differences? What are the requirements for planting time, watering and bed preparation?

You can plant petunias from September through early November and from late January through mid-March. They do better during winter months in south Louisiana. Their performance through winter depends significantly on how cold the winter is.

Petunias are available in many colors. They come in single-flowered and double-flowered varieties. Normally, the single-flower forms are more reliable than the double-flower forms long-term.

Some best management practices for petunias include:

– Properly prepare the bed to allow for good internal drainage and aeration.

– Add fresh, nutrient-rich, finished compost to beds to provide nutrients.

– Apply a slow-release fertilizer at planting as part of a traditional fertilizer approach.

– Make sure petunia beds have a soil pH between 5.5-6.0.

– Select a full-sun planting location. If you want to extend petunias longer into summer, plant in a partially shaded location but realize flowering will be less.

– Complete late-winter and early-spring petunia planting by mid-March.

– Consider the Wave, Easy Wave, Tidal Wave and Madness varieties. Many others will, however, provide satisfactory performance.

– Irrigate only when needed. Over-watering leads to root rot and stem dieback problems.

– Be aggressive and plant in masses for the best visual enhancement.

–Deadhead lightly after the first peak bloom for performance longer into late spring.

Petunias are popular bedding plants and are not difficult to grow. Just follow these recommendations and select nice, vigorous, healthy plants to get started.

Visit LaHouse in Baton Rouge to see sustainable landscape practices in action. The home and landscape resource center is near the intersection of Burbank Drive and Nicholson Drive (Louisiana Highway 30) in Baton Rouge, across the street from the LSU baseball stadium. For more information, go to www.lsuagcenter.com/lahouse and www.lsuagcenter.com/lyn.

Rick Bogren