The Petunia - Old Standby or New Favorite?

 Kay Hinkle
Adams County Master Gardener

One of my favorite flower memories from childhood is the dark, velvety surface of the purple petunia that my best friend's mother grew in her flowerbeds near Wenksville in Adams County, Pennsylvania. And then there were the pots of red geraniums mixed with white petunias draped with vinca vines that dressed my mother's sidewalk in Bendersville just a few miles away. While I like to think that what I have learned about landscape design takes me into the 21st century, petunias still play an important role in the flowerbeds at my present home in East Berlin.

Lest you think that this is just an Adams County story, I can assure you that the petunia and its many new generations continue to be a favorite for much of the country. In fact, in many southern states the petunia is viewed much like the pansy, as a good, cool season bedding plant.

In South Central Pennsylvania, the petunia is viewed as a versatile heat-resistant, drought-resistant annual that blooms in mass profusion in beds, pots and baskets during the summer months into autumn. The color range is huge, with varieties available in almost every color but orange. Petunias can be used as cut flowers, but they look best in garden displays.

While the velvety purple petunia and the mixed pots of red and white of my childhood still have a certain appeal to many of us, the color selection, growth habit and variety of uses for the petunia have grown significantly. They cascade and wave, even serving as a kind of annual ground cover for certain applications.

Two general classes of petunias are Grandiflora and Multiflora. Grandiflora petunias are characterized by having fewer, but larger, showy flowers. A number of Grandifloras are cascade selections, well suited to growing in hanging baskets, window boxes and other planters. Multiflora petunias have a more compact growth habit and small, but more numerous, flowers. The Multifloras withstand wind and hard rain better than the Grandiflora types. There are hundreds of petunia varieties, or cultivars, available. Local landscape nurseries usually handle those varieties best suited to local environmental conditions.

Petunias can be started from seeds and are best started indoors because their very fine seeds are hard to handle. When they are 1-2 inches tall, the seedlings can be transplanted outdoors 6-8 inches apart in well-drained soil (at least 60 degrees Fahrenheit) after all danger of frost has past.

Pinch the seedlings at a height of 3-4 inches to encourage bushy growth. Over watering will cause yellow leaves; over fertilizing will result in an abundance of foliage with fewer flowers. Limit supplemental feedings to once or twice during the growing season.

Once during the growing season after the initial flush of bloom, you may want to cut the plants back to encourage a second blooming. The Grandiflora varieties should be "dead-headed" - the practice of pinching off spent blooms - on a regular basis. You may find that the Multiflora cultivars do not need this kind of care to promote bloom.

Petunias flourish in a sunny, well-drained location and do well in all but the coldest climates. They bloom from summer into autumn in the Northeast and all year round in the sunny South. They are relatively disease and insect resistant as well, making the petunia a very popular choice in landscapes everywhere.

One of my particular favorites is the wave petunia. Since a local nurseryman recommended them for some rather large flower boxes built into my deck, I have planted them year after year. They withstand the weather, from hot noonday sun to heavy winds and rains, with nary a ruffled leaf.

I plant my wave petunias before Memorial Day and give them a haircut around July 4th. Because of their tendency to spread, I plant fewer flowers than I would if I chose a more upright flower, making them a good buy for my landscape dollar. They continue to bloom profusely until the first frost with little care required, allowing me extra time to tend more temperamental plantings.

This year, several new blue shades are available so that my former pink, rose or lavender color choices can be augmented. Last year's petunias have re-seeded themselves, so that the color mix in my boxes this year will be a bit of a surprise. The seedlings that mature will vary from the shades previously planted because the petunia is a hybrid and will not reproduce true to color. The focus will still be the deep blue hue of the newly planted cultivar.

Now that my widowed father has given up housekeeping (and planting) in Bendersville, he lives with us in East Berlin where he recently planted this year's petunias in my flower boxes. Always more of a geranium man, he is pretty pleased with his part in keeping alive my memories of the ever-popular petunia from this end of the county. I expect he'll come over to the petunia side once he sees the "waves" that result from his planting this year.

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