The Gardener's Companion: How to Grow Wave Petunias
During my time as a greenhouse owner, I had numerous customers come to my place looking for something easy to grow that would be hard to kill. Obviously, with any plant, there is the potential to not meet some of its needs and thereby kill it. But over time, I realized there was one that was preferred over most others: the wave petunia. This easy-growing plant is a great starter plant for any novice flower gardener.
The wave petunia blends the habit of the petunia and a trailing vine plant. The flowers are characteristic of the original petunia, in multiple colors of white, pink, red, purple, and yellow. These flowers bloom profusely throughout the growing season and do not require plucking the way a traditional petunia would.
Wave petunias come in several varieties: trailing, mounding, and spreading types. They are good for containers and hanging baskets and will do fine planted directly in the ground. The trailing types will spread 2 to 3 feet. So plan your growing application accordingly.
Wave petunias prefer a full sun location. They will tolerate partial sun, but do not do well in the shade. Heat is not a problem, as long as you water and fertilize them sufficiently. You can check the soil with your fingers. If it is dry, there is a need for attention.
Growing From Seed
Wave petunias can be grown from seed, using a seeding tray and soilless mixture. The soilless mixture is preferred because it does not harden when wet (which makes the seeds fight for a place to grow). It is preferred to get pelleted seeds—those which are coated to allow them to be handled easier—as the seeds are tiny and difficult to work with by hand.
These types of plants will fall into what is known as a bedding plant. Your local greenhouse, garden center, or nursery will classify these as such because people treat them just like other ones, such as impatiens, marigolds, geraniums, standard petunias, and other flowering plants that fill flower gardens across the world.
Growing From Cuttings
The wave petunias will have fine, hair-like fibers along the stem that can develop into roots when placed in contact with potting soil or dirt. In fact, cuttings of wave petunias stuck into dirt, watered, and receiving sufficient heat (50–60˚F) will sprout roots in 7–10 days.
A word of warning, though, as this is only intended for growth at home. Doing this for commercial purposes would be a copyright violation for the developer of the variety.
Wave petunias are heavy feeders, meaning they like the fertilizer to be given frequently. In one of the reference books I used when growing for resale, I read about an experiment at a producer of liquid fertilizer where the petunias were fed two or three times the recommended amount of liquid fertilizer and thrived from the experience. Perhaps you should stick to the manufacturer’s guidance and only fertilize every 7–10 days though.
Why is it important to feed wave petunias? Won't they just grow if the weather is warm and I keep them watered? Yes, they will grow, but you will see the signs of malnutrition, which include faded color in the blooms as well as a yellowing in the leaves and stems. Remember, this is a fast-growing plant, which requires plenty of food to make the plant remain healthy looking and prosper in its push for floral glory.
Wave petunias are one of the best plants at telling on you when you neglect their needs. You don't want this humbling experience, so take care of your obligation by feeding the plant regularly. Trust me. For the reward the plant gives, this is not too much to ask.
I would put just about anything in a hanging basket with a wave petunia. The thing to keep in mind is that the wave petunia wants to use all the space. So you need something just as vigorous, or the wave petunia can choke it out.
I have used trailing verbena, osteospermum, dracena (spikes), geraniums, ipomoea (sweet potato vines, the flower variety), million bells, and more to combine nicely with these favorites of every gardener.
I sold a whopping amount of wave petunias in everything from a four pack to single 4-inch pots and quarts up to large hanging baskets. There really is no end to the possibilities with these plants.
Pinch Off Long Branches
When I grew the “waves”, as I called them, I would pinch the branches off as they began to get long on the first set of vines so the plant would become stockier. You can see a plant that is unattended at the local garden center or big box store, as it will have thin little vines that are easily broken by handling or the wind. In contrast, plants that have been pinched will weather the summer much better, sustaining all but exceptional wind and storms
Give Them Plenty of Growing Space
Wave petunias will grow fast and become root bound within a short time. So if you buy individual plants, make sure to provide them with a pot that has plenty of growing space. If you will take your plant out of the pot about six weeks after you start growing it, you will find the roots have wrapped around the bottom of the pot and filled in all the available space. If this happens, you can take a knife and cut the bottom half of the roots off the root system to allow for more growth space. Don’t worry, this will not kill the plant, but actually will invigorate it.
Make Sure It's Fertilized and Drains Well
Also, as the plant matures, it will require more fertilizer to preserve the dark green color you desire. Be careful to put the petunia in a well-drained pot, as too much water will leave the soil wet and turn your plant yellow. If this happens, hold off on watering and get the plant in full sun to dry it out.
Wave petunias can be found all over the place in the spring and fall, covering many places with a beautiful carpet of color. They are a favorite of landscapers because two or three can easily cover a 5- to 6-foot diameter area. They are hearty, growing continuously from mid-spring until killed by frost.
Enjoy the experience of planting wave petunias, perhaps the easiest flower you will ever grow.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2010 Dobson