How to Deadhead Petunias in 5 Simple Steps

Petunias are known for continuously displaying blossoms from the moment you plant them until the first frost. This is their most treasured feature and what most gardeners are after. The blooms come in many colors ranging from white, red, pink, and purple to multicolored.

These flowers are fairly low-maintenance if provided the proper sunlight, watering, and pruning. They look excellent in hanging baskets, containers, landscapes, flower beds, and vegetable gardens. There are endless options for where to grow these flowers as long as they have proper conditions. 

With so many different varieties to choose from, how should you begin to narrow down the search? One thing to remember is that some varieties are self-cleaning while others are not. Self-cleaning varieties will drop the spent flower before it goes into seed production. Other varieties need deadheading. 

If your plants are not self-cleaning, you may wonder what deadheading is and how to do it. In this article, we will explain how to deadhead your petunias to make them look beautiful all season long. 

Step 1: Why Deadhead?

Deadheading removes flowers that have finished their life cycle and begun to wilt and die. If dead blossoms are left on the plant, they will begin to produce seeds. Seed production takes a lot of energy away from the plant. 

This means less energy is going into making more flowers. Deadheading will keep the plant clean but also increase flower production. Who doesn’t want more blooms?! 

But if you are interested in your petunias going to seed, you can leave the spent flowers on the plant. This will result in fewer new flowers and may give the petunia a less-appealing appearance. Without deadheading, your plants will display more brown and wilting blooms than fresh, colorful flowers. 

Step 2: Understand Varieties

Not all petunias will need to be deadheaded. Spreading varieties (labeled “self-cleaning”) won’t require deadheading. They will drop their dead flowers from the plant and keep producing blooms. Self-cleaning cultivars include:

• Supertunia® series
• Wave® series

Other varieties will require you to remove the spent flowers. Petunias that form a mound or have more of a mounding tendency will require deadheading throughout the season. There are five different types of petunias, and they all behave and grow differently. The categories are:

1. Grandiflora (they have the biggest flowers but need regular deadheading)
2. Multiflora (smaller flowers, compact growth, and prolific blooms benefit from deadheading)
3. Floribunda (these hybrids require less deadheading)
4. Milliflora (best for containers and require minimal pinching of flowers)
5. Trailing (vining types prefer to be deadheaded)

There are a few things all types share:

1. They all have a very long bloom window.
2. They all love full sun and thrive best if exposed to 6 hours or more of sunlight per day.
3. They all attract pollinators such as hummingbirds, bees, and butterflies. 

If you don’t want the extra maintenance of deadheading, plant a self-cleaning variety.

Step 3: When To Deadhead 

There is no hard and fast rule on when you should deadhead. Usually, blooms last a couple of weeks before they begin to fade. It’s all based on the time of planting and the weather. 

Once you notice blooms beginning to fade in large numbers, consider deadheading to keep the plants looking clean. This will encourage new flowering, and your plants should produce another flush of blooms shortly. 

You may have to deadhead weekly or biweekly to keep plants neat and clean. It ultimately depends on how much time you want to spend in the garden. The great thing about these plants is they will keep growing if you don’t deadhead. However, they might not look as healthy compared to a regularly deadheaded plant. 

Step 4: How To Deadhead 

It’s time to deadhead once you notice that your plants have several wilting or brown flowers. Begin by gathering and cleaning sharp scissors or a knife. You can remove spent blooms by hand, but scissors or a knife will make it easier.

If you remove by hand, be careful not to rip whole steps or accidentally put a whole plant out. Pinch the base of the flower firmly with a finger and a thumbnail to cut through the stem. Do not grab and pull straight up. This motion can cause you to uproot the entire plant from the soil. 

Locate the spent blooms and cut the entire flower from the stem. The base of the flower is called the sepal and has small green leaves around it. You want to remove these small leaves along with the petals, as the sepal is where seeds form, and you’ll start seeing seed development shortly after the flower fades. It may be easiest to follow the flower’s stem back to the nearest leaves and cut just above them to remove the spent flower.

While deadheading, you can also cut back any stems that are beginning to look leggy. This will also help with bloom production and keep your mounding varieties compact. 

Step 5: Repeat When Necessary

Since petunias keep reblooming once you deadhead, you will have a continuous cycle of new blooms and blooms that need to be removed. I mentioned early that petunia flowers have about a 2-week life cycle. You can expect to be deadheading your petunias pretty regularly. 

Don’t panic if you forget for a couple of weeks. The plants will still have beautiful, fresh blooms that will outshine the faded flowers. Setting reminders or writing them down on a calendar helps keep me on track. Find a deadheading schedule that works for you and won’t drive you crazy. 

Petunias bloom from spring to the first frost in the fall. Don’t remove the spent blooms if you want to allow your petunias to go to seed. I recommend leaving spent blooms towards the end of the season to allow the plants to reseed. Remember that the seeds will only survive the winter in warmer regions. 

Frequently Asked Questions