Petunias are one of our favorite flowers, and with good reason: they're available in a wide array of bright, cheery colors, and their trumpet-shaped blooms look amazing filling in a flower bed or spilling from a planter or hanging basket.
To ensure that your petunias bloom throughout the growing season and look their best, you'll need to deadhead them, or remove spent flowers, every once in a while. Here's how to deadhead petunias and keep them flowering all season long.
Meet the Expert
Alexandra Jones is a certified master gardener in Philadelphia. As an indoor and outdoor gardener, Jones is an author in topics like gardening, climate, urban farming, and sustainability.
- Working time: A few minutes to one hour, depending on the number of plants
- Total time: A few minutes to one hour
- Skill level: Beginner
Why You Should Deadhead Petunias
It's important to deadhead your petunia plants if you want to enjoy new blooms throughout the growing season. Because flowering plants stop blooming once they've released seeds, removing faded or dried-out flowers from petunias tells the plant it's time to create new flowers.
It's especially important to deadhead petunias grown in containers to ensure a longer bloom period. And large gardens with many petunia plants, or multiflora or milliflora varieties (which can have dozens or even hundreds of flowers on a single mature plant) may be impractical to deadhead regularly.
Note that some types of petunias don't technically need to be deadheaded, as they've been bred to bloom vigorously without this maintenance. Wave petunias, which spread widely but only grow six inches tall, are one such variety. Specially bred Supertunias also do not need deadheading.
You can also plant similar but lower-maintenance flowers to get the same effect. Calibrachoa flowers look and grow very similar to petunias, but are a different species. Because they don't need deadheading, they've become a popular substitute. You may still want to remove spent blooms from calibrachoas or petunias that don't need deadheading simply to make the plants look better.
When to Deadhead Petunias
When your petunia plants start to bloom in late spring or early summer, keep an eye out for any shriveling, wilding, or dead blooms. As soon as you see any flowers fade, it's a good idea to remove them. Leave still-fresh blooms alone until they start to die back.
If possible, plan to deadhead your petunias once per week during the growing season. If that's not possible, try to deadhead them at least once in midsummer to keep them going. At this time, you can also cut back any leggy stems, which will also promote floral growth.
Tools and Supplies You Will Need
Before you begin, gather the following materials:
- Protective gloves (some petunia varieties give off a sticky sap)
- Clean, sharp scissors, shears, or pruners
Step 1: Identify Dead Petunia Blooms
Examine your petunia plants for flowers that look faded or past their prime. Dead petunia blossoms will look wilted, shriveled, brown, or dried out, while thriving blooms will be colorful, perky, and open.
Step 2: Remove Dead Petunia Flowers
Look behind the faded flowers to the area where the flower meets the stem, also called the sepal. This green, leafy-looking structure is where the seeds form. Removing this area before the seeds have set will tell the plant it's time to grow more flowers.
Use your pruners to snip the stem just below the sepal. Do this with each faded or dead petunia blossom. Look for empty sepals where dead flowers may have already fallen off and remove those too. You can also trim away any leggy, green stems. Be sure to avoid cutting off any fresh blooms or unopened buds as you work your way through your petunia plants.
While you can remove the occasional spent bloom from your petunias by punching them off with your fingers, it's generally recommended to use scissors or pruners to avoid damaging the plant.
Step 3: Enjoy New Petunia Blooms
If you've had trouble keeping petunias blooming in the past, a weekly deadheading session should give you abundant blooms all season long. If it's been several weeks since you deadheaded, it may take a week or two for you to notice new growth after deadheading.