Petunia Flowers: How to Plant, Grow, & Care for Beautiful Blooms
A guide to growing gorgeous petunia flowers in your garden or in containers Updated 1/26/2022Supertunia 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.
2024 Annual of the Year:
Supertunia Vista® Jazzberry® petunia.
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.
Exposure:
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
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
FREQUENTLY ASKED QUESTIONS
Do deer eat petunias?
Yes, deer do eat petunias, especially when other food is scarce. If deer visit your garden, consider protecting your petunias with repellents or fencing. Learn more on how to protect your garden from deer.
Do rabbits eat petunias?
Yes, rabbits like to eat petunias. If you have rabbits around, protect your petunias with barriers or natural repellents to keep them safe. See more natural ways to protect your garden from rabbits.
Are petunias poisonous to dogs or cats?
Not to worry—petunias are safe for dogs and cats. However, it's always best to discourage them from eating any plants to prevent any possible stomach upset.
Do petunias need full sun?
Petunias love sunshine and grow best in full sun (6-8 hours a day). Planting them in a sunny spot ensures they stay healthy and full of blooms. They can tolerate some shade, but just might have fewer flowers.
Do hummingbirds like petunias?
Yes, the bright colors and funnel-shaped flowers make them appealing to hummingbirds. See more flowers for hummingbirds.
Also: Learn how to plant, grow, and care for petunias in pots.