How to Plant, Grow, & Care for Petunia Flowers
A guide to growing gorgeous petunia flowers in your garden or in containers Updated 1/26/2022
Supertunia Vista® Bubblegum® grows at the front of this landscape bed. Photo courtesy: Proven Winners.
When I was growing up, my grandmother introduced me to purple grandiflora petunias, which she brought home from the nursery by the dozens to brighten up her summer garden. They were the first flowers I ever planted, and I have been madly in love with petunias ever since.
Today, there are even more reasons to fall in love with them because there are so many more choices. From compact types with dime-size blooms to spreading or trailing varieties that reach to 4 feet, they now come in a wide variety of colors, sizes, petal profiles, and growth habits. This new-generation has also been bred to outperform their predecessors, producing nonstop blooms all summer long on sturdier, easy-to-grow plants.
On this page: Basics | Planting | Care | Petunia Pictures | Types | Design Ideas
On this page:
BASICS
Are petunias perennials or annuals?
Although they are actually classified as tender perennials, they won't tolerate frost so they are commonly grown as annuals in most climates.
Sun or shade?
Full sun
Bloom time:
Summer
Color and characteristics:
You can find them in just about any color, even black, as well as striped, veined, and speckled patterns. The variety of flower forms is also impressive, ranging from petite to palm-sized in single or double blooms with ruffled, fringed, or smooth edges.
HOW TO PLANT PETUNIAS
When to plant:
In spring, after the threat of frost has passed.
Where to plant:
For the best performance, plant in full sun (at least six hours a day). They will tolerate some shade, but may not flower as prolifically.
Soil:
They grow best in a light, fertile soil that provides good drainage and is slightly acidic (pH 6 to 6.5). In heavy clay soils, work some compost, or other organic matter into the ground before planting. When planting in containers, use a free-draining soilless potting mix fortified with a slow-release fertilizer.
Grow petunias from seed:
You can also grow many types from seed if you’re after a certain variety not available as a transplant. Because petunia seeds are very tiny and slow to germinate, you’ll have better success starting the seeds indoors 8 to 10 weeks before the last frost date in your area and transplanting the seedlings into the garden once the soil warms up.
PETUNIA CARE
Water:
Petunias need regular watering because their shallow root systems dry out quickly. However, make sure the soil is well drained because soggy soil can cause root rot and yellowed foliage. Petunias grown in containers may need more frequent watering, possibly every day, especially in hot weather.
Fertilizing:
To keep petunias blooming vigorously throughout the summer, apply a monthly dose of liquid fertilizer or a slow-release granular fertilizer at the time of planting. Plants in containers often need more frequent fertilizing because the nutrients get washed out.
Pruning and deadheading:
The amount of pruning required often depends on the variety you’re growing.
- Traditional grandifloras require the most work and need frequent deadheading to prevent plants from going to seed.
- Self-cleaning and spreading varieties do fine without pinching or pruning. Occasional deadheading will boost flower production and create fuller plants.
- If your plants begin to get leggy and have fewer blooms, cutting them back will encourage new growth and more branching.
For more, see: How to Deadhead Petunias and How to Prune Petunias.
Pests and diseases:
Petunias can be bothered by pests like aphids, thrips, mites, caterpillars and budworms; as well as powdery mildew.
Get more advice on keeping your petunias blooming all summer long.
PETUNIA PICTURES
Photo: Proven Winners
Supertunia Vista® Bubblegum® — Buy now from Proven Winners
Rock stars in the landscape, the Vista® series makes a huge visual impact. Bubblegum® forms a thick carpet of pink blooms that will quickly cover any empty, sunny space in the garden. Its stems will easily grow three feet long in a spreading mound.
Height:
12 to 24 inches
Spread:
24 to 36 inches
Photo: Proven Winners
Supertunia® Royal Velvet® — Buy now from Proven Winners
It's easy to see why this is a top seller! Royal Velvet® is heat and drought tolerant and produces an abundance of deep purple flowers that attract hummingbirds and butterflies. Pair with just about any other color in beds, hanging baskets, and containers.
Height:
6 to 12 inches
Spread:
18 to 24 inches
Photo: Proven Winners
Supertunia® Bordeaux™ — Buy now from Proven Winners
The dramatic veining pattern of this purple petunia is unlike any other. This award-winning annual is prized for its vigor and ease—no deadheading required. Grow on its own or pair it with other strong growers like Superbells® Calibrachoa or Superbena® Verbena.
Height:
6 to 12 inches
Spread:
18 to 24 inches
Photo: Proven Winners
Supertunia Mini Vista® Pink Star — Buy now from Proven Winners
This vigorous grower will be the star of your garden with cheery pink and white striped flowers. Heat and drought tolerant, they'll provide a garden pick-me-up wherever you need it.
Height:
6 to 12 inches
Spread:
18 to 24 inches
2021 National Annual of the Year
Photo: Proven Winners
Supertunia® Black Cherry® — Buy now from Proven Winners
This stunning semi-trailing petunia is covered by cherry-red flowers with black accents from spring until frost. Plant in hanging baskets or containers and allow it to spill over the edges. Combine with Supertunias® Bordeaux™ and Vista® Fuchsia.
Height:
6 to 12 inches
Spread:
24 to 30 inches
Photo: Proven Winners
Supertunia® Sharon — Buy now from Proven Winners
A double petunia hybrid, Sharon is heat tolerant and long blooming. Show off the bi-color pink blooms in window boxes, hanging baskets, planters, or at the front of a mixed bed or border.
Height:
6 to 12 inches
Spread:
18 to 24 inches
Photo by: Luisa Fumi / Shutterstock.
Petunia Night Sky®
White speckles on a deep-purple backdrop give this mesmerizing petunia the look of stars twinkling in the night sky. The variance between day and night temperatures causes the luminous white stars to appear in constantly changing configurations.
Height:
10 to 13 inches
Spread:
20 to 30 inches
Photo courtesy: All-America Selections.
Tidal Wave® Silver Petunia
Dazzling silvery white blooms with dark purple centers and delicate purple veining. Even more impressive is the plant’s ability to be used as a hedge, climbing vine, or fast-growing groundcover.
Height:
16 to 22 inches
Width:
30 to 60 inches
Photo by: GWI/Botanic Images Inc. / Age Fotostock.
Cascadias™ Autumn Mystery
A semi-trailing petunia with an ever-changing combination of colors. The blooms open with pale yellow petals and mahogany-brown centers, and gradually fade to cream and deep purple. Also boasts a long bloom season, from late spring to early fall.
Height:
12 to 14 inches
Spread:
16 to 20 inches
Photo courtesy: All-America Selections.
Wave® Carmine Velour
Lauded for its velvety carmine-rose blooms that remain vibrant, come rain or shine. Large flowers, 2- to 3-inches, cover the entire plant, creating a blanket of color that lasts from spring until the first frost.
Height:
6 to 8 inches
Spread:
3 to 4 feet
TYPES OF PETUNIAS
Nearly all petunia plants sold today are hybrids. Some new petunia varieties and hybrids have become so popular, they have created a class of their own, such as the Supertunia®. (See more on how to grow Supertunias.)
Compare the different types of petunias.
IDEAS FOR USING PETUNIAS IN THE LANDSCAPE
Petunias are very popular flowers for adding instant color to a garden. They are incredibly versatile and can be used in many ways. Here are some ideas:
- Plant them as colorful additions to seasonal landscape beds
- Grow them individually in hanging baskets and window boxes or along with other strong growers
- Use them in containers as the filler or spiller component
- Plant petunias in masses for a dramatic blanket of color
- Cover bare spots in your garden quickly and prevent weeds
Also: Learn how to plant, grow, and care for petunias in pots.
