Wave Petunia

Plant Wave petunia transplants outdoors after all danger of frost has passed, in full sun with well-drained soil. Space plants twelve to twenty-four inches apart in garden beds, as each plant can spread three to four feet wide. In hanging baskets, use one plant per twelve-inch basket or three per large sixteen to eighteen inch container. Wave petunias need room to spread and should not be crowded with other plants.

These vigorous growers are extremely heavy feeders and require more fertilizer than typical annuals. In containers, feed weekly with a balanced liquid fertilizer at full strength or apply slow-release granular fertilizer at planting and supplement with weekly liquid feeding. In garden beds, feed every two weeks. Consistent nutrition is the key to the explosive growth and nonstop bloom that Wave petunias are famous for.

Water thoroughly when the top inch of soil is dry, which may be daily for containers in hot weather. Wave petunias do not require pinching, deadheading, or any shaping. Their naturally trailing and self-branching habit fills containers and covers ground without intervention. If plants become sparse in the center by midsummer, cut back by one-third and increase feeding to encourage a fresh flush of vigorous growth.

The Wave Petunia traces its ancestry to wild petunia species native to South America, primarily found in the grasslands and coastal regions of southern Brazil, Uruguay, and Argentina. Wild petunias (Petunia integrifolia and Petunia axillaris) were first collected by European botanists in the early 19th century and brought to European gardens where hybridization began in earnest by the 1830s. Traditional garden petunias were upright, mounding plants that required regular deadheading and tended to become leggy by midsummer. The development of the Wave Petunia represented a breakthrough in petunia breeding. In the late 1980s and early 1990s, plant breeders at Kirin Brewery Company in Japan, which maintained an active ornamental plant breeding division, developed a vigorous spreading petunia that could be grown reliably from seed. Ball Horticultural Company of West Chicago, Illinois, partnered with Kirin to introduce this new type of petunia to the North American market. The first Wave Petunia, a vibrant purple variety called Purple Wave, was launched in 1995 and was immediately recognized as a game-changing plant. It won the prestigious All-America Selections award that same year. Unlike traditional petunias, Wave Petunias spread vigorously along the ground or trailed dramatically from containers without the need for pinching, deadheading, or constant grooming. The Wave brand expanded rapidly through the late 1990s and 2000s, introducing new colors, patterns, and sub-series including Easy Wave, Shock Wave, and Tidal Wave, each offering slightly different growth habits and flower sizes to suit various garden applications. Today, Wave Petunias remain among the best-selling annual flowers worldwide.

Wave petunias require rich, well-drained soil or potting mix to support their vigorous growth. In containers, use a high-quality potting mix with perlite for drainage. Feed weekly with a balanced liquid fertilizer such as 20-20-20 at full strength, or apply slow-release granular fertilizer at planting and supplement with weekly liquid feeds. Wave petunias are among the heaviest feeders of all annuals, and under-fertilizing is the number one cause of poor performance and sparse blooming.

Wave petunias are not typically grown for cut flowers due to their trailing habit and short stems. However, small sprigs can be snipped for bud vases. Deadheading is unnecessary, as Wave petunias are self-cleaning and drop spent blooms naturally while producing new flowers continuously. For seed saving, note that Wave petunias are F1 hybrids and seeds will not produce identical plants. Propagation is best done by stem cuttings taken in late summer.

Wave petunias are best enjoyed in the garden or container rather than as cut flowers. Small cuttings placed in water will last three to four days. To preserve Wave petunias over winter in frost-prone areas, take four-inch stem cuttings in late summer, root them in moist perlite or vermiculite, and overwinter the rooted cuttings indoors in a bright window. This is often more reliable than saving seeds, which do not come true from hybrid varieties.