One of the most popular flowers today has also been a mainstay of garden history.

The petunia first became popular in this country during the 19th century. Discovered in South America, the petunia is a member of the Solanaceae (nightshade) family which also includes peppers, potatoes, tomatoes, eggplant and Datura spp.

Modern day petunias are all hybrids of two early species; Petunia axillaris (white) and Petunia violacea (purple-flowered). Both were introduced to Europe in the 1800s although they were nowhere near as spectacular as cultivars are today. Breeders began crossing these species in hopes of developing a petunia of other colors as well as those with larger flowers. Fortunately, they were somewhat successful in their efforts.

By 1900, double flowered petunias were produced although they were not “stable.” About the same time as European scientists were breeding double flowers that did not always stay true or reverted back to single flowering petunias, Japanese breeders jumped onto the band wagon. The first consistently double flowering petunias were developed in Japan; plants that would be true to type without vegetative propagation.

In the 1930s, many great scientific discoveries were made including the development of the grandiflora petunia by a German company. Using the methods of Gregor Mendel, scientists were beginning to utilize the principles of genetics and use of the parental genes of the Petunia genus to find new varieties. Charles Weddle of the still famous W. Atlee Burpee & Company was one of the first to fully develop a double flowering petunia using this theory.

As with many scientific efforts, World War II caused those experiments take a back seat to more important issues. After the war, an effort was made to develop plants that flowered in a wider variety of colors, had better branching, were more resistant to disease, and with flowers that had better tolerance to drenching rains.

The early attention paid to this special plant has resulted in numerous types of petunias available on the market today. In particular, the spreading, heat tolerant, self-cleaning types are useful to us in the Miss-Lou. The “Wave” series is one that has shown itself to be a fabulous addition to our gardens.

Useful as ground covers, container specimens, trailing from the edge of a large container, or as accents in a walk path, these spreading petunias are not only beautiful but exceptionally tough during our hot summers. Several petunia series of this type can be found at your local nursery today. With minimal attention these petunias will not only last through spring, but they will continue flowering at least until the first autumn frost.

Unlike the historical double and giant flowered petunias, these have smaller but more abundant blooms. Additionally, their heat tolerance is incredibly strong. Transplants will flower and spread to two feet or more. Although lower growing than more historical varieties, these petunias have an unbelievable show of flowers.

So what’s the secret as far as keeping these Miss-Lou tough plants producing? Simplicity. Allow the plants room to spread. Cut them back by two-thirds after flowering to keep them from spending all of their energy setting seed. After a couple of weeks (even in July or August), you will enjoy their floriferous experience again. Pruning as they become leggy and naturally want to set seed is a key to success. You may even experience these spreading petunias flowering during winter, as cool temperatures are not a foe.

Plant petunias in plenty of sun and make sure they are in a well-drained environment. Other than that, enjoy!

Traci Maier writes a weekly gardening column. She can be reached at ratmaier@bellsouth.net.