By JAN MAAS, Beltrami County Master Gardener
It’s no wonder petunias continue to be a favorite annual for our gardens and pots. Petunias offer enormous choices and varieties. There are single and double blooms, veined, striped, ruffled, mounding, spreading and cascading. Plus, they have a sweet spicy fragrance. Petunias are available in all colors except a true blue and black. So when you get to the garden center and decide to get a few packs of petunias how do you choose the right variety for your needs?
First consider that petunias require lots of sun, at least 5 to 6 hours a day. If they get less than that, there will be fewer blooms and they can get leggy. If the summer gets really hot, they will tend to produce fewer flowers.
The grandiflora petunias are one of the oldest varieties. They produce the largest blooms (4 to 5 inches across) and grow about 8 to 12 inches tall. The flowers take a beating from heavy rain and need to be deadheaded regularly to keep them blooming. They also will benefit from a trim later in the summer to keep them blooming until frost. Grandifloras do well in containers and beds.
Multiflora petunias have a more compact growth habit and produce smaller flowers. The blooms are more prolific and hold up better in the rain. There is a wide range of colors available and these are a better choice to put in flower beds.
The Wave petunias produced quite a stir when they were first introduced in the 1990s and have continued to be improved. They only grow 6 inches tall, but can spread to about 4 feet. They are great ground covers and look lovely trailing from containers. Waves don’t need deadheading, but they can “wear out” in midsummer and will benefit from a little pruning to revive them. The colors available have grown year by year from that first “purple wave.” There is also the “Tidal Wave” series which produces plants that are a bit more upright, as well as the “Easy Waves” which are more compact and “Shock Wave” which produces smaller flowers.
Cascading and Surfinia petunias are two types that were bred for their trailing habit. They are easy care and do best in hanging baskets trailing to about 18 inches. These types also are available in a wide range of colors and shadings.
Supertunia petunias are vegetatively propagated, meaning they are produced from cuttings, not seeds. They are part of the Proven Winners series. Supertunias are similar to the Wave petunias, but tend to not spread as much and cascade a little better from a container. They are prolific bloomers and if kept well fertilized, will bloom and bloom. They are also weather tolerant.
Calibrachoa or “Million Bells” looks to be a miniature petunia, but is actually an entirely different species. They were originally found in coastal areas and were once called “seashore petunias.”
Petunias are wonderful annuals to grow and with a little care will bloom from early summer to frost. With so many varieties and colors surely there must be one or two that will work in your garden.
Look for information about horticulture on the University of Minnesota Extension Home and Garden Information page www.extension.umn.edu/gardeninfo or on the Beltrami Master Gardener site beltramicountymastergardeners.org. The local Master Gardener horticultural assistance voice mail is again taking calls at 444-7916 with your question.
