How to Choose the Right Type of Petunia

Several pots of petunias sitting on a picnic table.

Westend61 / Getty Images

Petunias have been garden favorites for decades. These annual flowers bloom almost nonstop throughout the summer. Traditional petunias favored cool weather and needed constant deadheading to continue blooming. More recent introductions, such as the wildly popular wave petunias and the petunia look-alike Calibrachoa, or Million Bells, are much more carefree and low maintenance.

Today's petunias offer enormous variety: single and double blooms, ruffled or smooth petals, striped, veined or solid colors, mounding and cascading habits, and even some with old-fashioned ​fragrance. Most of the petunias sold today are hybrids, developed for specific design purposes, such as bed edging, cascading over hanging baskets, or covering the ground. It's hard to go wrong choosing a petunia these days, but here's some advice for pairing your petunia with your particular design need.

  • 01 of 06

    Grandiflora Petunia

    Petunia grandiflora in bloom.

    Frederic Didillon / Photolibrary / Getty Images

    Grandifloras are one of the oldest varieties. These petunias grow 8 to 12 inches high and have the large (4 to 5 inch), wavy-edged blossoms that petunias first became known for. The flowers can be single or the more ruffled doubles. Grandiflora petunias have the largest flowers, but the flowers get pummeled by rain, turning to a mushy mess that makes them unpleasant to deadhead—and they will need to be deadheaded if you want them to continue blooming. If the spent flowers are left on, the stems will grow long, but no new buds will form. However, there are some standouts, such as the buttery yellow 'Prism Sunshine,' that are so stunning they are worth the effort. Grandifloras work well in both beds and containers.

  • 02 of 06

    Multiflora Petunia

    Multiflora petunias in bloom with cascading vines.

    Michael Davis / Getty Images

    Multiflora petunias have a more compact growth habit than grandifloras. The flowers are smaller, about 2 inches in diameter, but more prolific, and they hold up better against rain. There is also a wide range of colors. Because of their mounding habit, multiflora petunias are a better choice for garden beds than grandifloras and they work very well in containers.

    There are also hybrids of grandiflora and multiflora petunias, which share qualities of both types. A whole new category was created to describe them, known as the floribundas. The floribunda 'Madness' series that was introduced in the 1970s had grandiflora-sized flowers and multiflora weather tolerance. Today you can find floridbunda petunias with either small or large flowers.

  • 03 of 06

    Wave Petunia Series

    Pink wave petunias in rose color.

    Serres Fortier / Flickr / CC BY 2.0

    The wave series created quite a stir when first introduced and the flowers just keep improving. Wave petunias grow only 6 inches tall but can spread to 4 feet. That feature would be enough to make them worth growing, but wave petunias also do not need deadheading. On the downside, they do wear out in the hottest part of the summer. Prolonged heat diminishes flowering in wave petunias, but a little pruning will usually revive them. Wave petunias make wonderful groundcovers and trailers for containers. There is also a 'Tidal Wave' series, which tends to stay a bit more upright.

  • 04 of 06

    Supertunia Petunias

    Light purple supertunia petunia.

     Serres Fortier / Flickr / CC BY 2.0

    The Supertunia series is vegetatively propagated, meaning it is grown from cuttings and does not grow true to seed. Supertunias are part of the Proven Winner plant line. Supertunias are extremely vigorous growers and bloomers, but they require frequent feeding to stay at their peak. However, if you feed them a little whenever you water them, or at least once a month, they will bloom and bloom. Supertunias are also weather-tolerant.

    Continue to 5 of 6 below.
  • 05 of 06

    Cascadia and Surfinia Petunias

    Blossoming white surfinia flowers

    PATSTOCK / Getty Images

    Cascadia and Surfinia are two more popular types of petunias. These are bred for their trailing habit, vivid colors, and prolific flowering. They generally have the wide flowers of traditional petunias, in unusual colors. You'll find lots of interesting shading and veining with these petunias. They are also easy to care for and spread or trail to about 18 inches. These petunias are best suited for hanging baskets and window boxes.

  • 06 of 06

    Calibrachoa (Million Bells, Superbells)

    Dozens of pink Calibrachoa petunias in bloom.

    Maria Mosolova / Getty Images

    Calibrachoa (Million Bells or Superbells) look like tiny petunias, but they are an entirely different species. However, they are increasingly popular and may just suit your purpose in a hanging basket. The tiny flowers cover the foliage and Calibrachoa hybrids share the best traits of hybrid petunias: long blooming, no deadheading, and weather tolerance. They also come in unusual petunia colors, such as gold and terra-cotta.