How to Bring Dried Out Petunias Back to Life
Petunias (Petunia spp.) are classic flowering plants grown for their fragrant, funnel-shaped blooms, which come in every color except black and brown. Petunias, which flower from spring to frost, are prized in large part because of their extended bloom time.
While petunias that are completely dried out cannot be revived, with some pruning and fertilizing, it is often possible to rejuvenate plants that have become leggy and stopped blooming during the summer months.
Are Petunias Annuals or Perennials?
Petunias are considered tender perennials. That means that while they are capable of surviving for multiple growing seasons, they can only do so in warm, frost-free climates in U.S. Department of Agriculture zones 10 and 11. As a result, in most of the U.S., petunias are treated as annual plants.
Most types of hybrid petunias do not come true from seed, so some gardeners may choose to overwinter prized plants.
Types of Petunias
The majority of petunias on the market are hybrid cultivars. Grandiflora petunias are popular hybrids that have large blooms that may be up to 4 inches in diameter. Multiflora hybrids produce more flowers than the grandiflora variety, but the blooms are smaller, measuring about 2 inches across.
If you are looking for a plant that is even more compact, consider milliflora petunias, which have flowers that are about an inch wide. These plants rarely become leggy.
There are also spreading, pendulous varieties of petunias that can be grown as groundcover and also work well in hanging baskets and window boxes.
Rejuvenating Petunias in Summer
In some cases, petunias may become leggy, which means that they grow tall and spindly as opposed to compact and bushy. When this happens, the plants may flop over and stop producing flowers. Petunias may become leggy if they do not receive full sun, which means six to eight hours of sunlight a day.
Growing petunias in full sun can prevent them from becoming leggy.
You can rejuvenate a petunia that has become leggy and stopped blooming by cutting the plant down to leave just a few inches at the base. Be sure not to remove all the petunia leaves, however, as the foliage synthesizes the sugars that the plant needs to survive and grow.
After cutting back the plants, fertilize them with a balanced liquid fertilizer and water the roots well to encourage new growth and flowering.
When petunias become leggy, cut them down to about half their size, leaving a few leaves attached to the plant. Fertilize and water the plants after pruning.
It is also a good idea to remove spent flowers, which is known as deadheading. This will encourage the development of new flower buds and prolong bloom time. Pinching grandiflora and multiflora petunias can also help these plants grow bushier and less spindly. Smaller petunia cultivars don't need to be pinched.
How Often to Water Petunias
While petunias require little care, maintaining medium moisture throughout the growing season will help keep the plants from drying out in the first place. During dry spells, give petunias about an inch and a half of water each week.
Petunias grown in hanging baskets or other containers require more frequent watering, whenever the soil is dry to the touch.
Since beginning her career as a professional journalist in 2007, Nathalie Alonso has covered a myriad of topics, including arts, culture and travel, for newspapers and magazines in New York City. She holds a B.A. in American Studies from Columbia University and lives in Queens with her two cats.