How To Deadhead Zinnias (Quickly & Easily!)

How to Deadhead Zinnias

Zinnias are bright, colorful annuals that thrive in the summertime, are relatively easy to grow and attract butterflies. Typically, these single-stemmed beauties grow for one season, from mid-summer till about the start of winter. 

Deadheading your zinnias regularly helps the flowers continue to bloom and stay healthy throughout the season. You can also use deadheading to encourage the flowers to grow taller, bushier, or closer to the ground. 

Deadheading can help your zinnias thrive, increasing the likelihood that they bloom throughout the season. However, it’s always a good idea to arm yourself with the basics first to ensure you understand the process. 

What Is Deadheading and Why Should You Do It?

Deadheading is the process of removing old, damaged, or dying blooms from plants to encourage new flowers to grow. Leaving wilting blooms on your plants can inhibit further growth, so it’s out with the old, in with the new.

Deadheading helps improve the overall aesthetic of your garden, as well as keeps your plants healthy. Typically, you should deadhead plants once or twice a week during the growing season. This continuous practice helps you keep an eye on your garden, which also helps with overall maintenance and upkeep. 

Growing Zinnias

If you’re an amateur gardener, zinnias are a perfect flower for you because they’re reasonably easy to grow. When growing them from seeds, there’s very little prep, and you can expect flowers in a few short weeks. Plus, zinnias do well in warm weather, so they’re a great choice if you live in a warmer climate.

When planting zinnias, the best time to do so is at the start of warm weather, such as early spring. Although depending on the climate where you live, late autumn might be a better option for you. 

Like many plants, zinnias need the right combination of several factors to promote optimal growth. Here are the basics to ensure you get a lovely batch of zinnias in your garden. 

Zinnias Need Lots of Sun

Zinnias love full sunlight, so find a place in your garden that doesn’t have a lot of shade. However, if you live somewhere that’s warm most of the time, some afternoon shade now and then can be helpful. This occasional shade can provide a little relief from excessive heat. 

Zinnias Need Moist Soil and the Right Spacing

If you live in a warm climate, you can seed zinnias directly in the soil after the last frost. However, if you live in a cooler climate, starting your plants indoors is best. You can use a germination tray, available at your local garden store or online, for about $20. 

No matter where you seed your zinnias, place the seeds about ¼” deep in the soil. The soil needs to be moist but well-draining, ideally with a pH level between 5.5 and 7.5. 

This range allows the flowers to absorb nutrients efficiently. However, you can adjust the pH if needed to accommodate nearby plants. The seeds should be at least 6 inches apart, and each row roughly 12 to 24 inches apart. This spacing allows for optimal airflow and growth. It’s essential to keep the soil moist, up to 8 inches deep. 

Don’t Overwater Zinnias

While zinnias thrive in soil that is moist up to 8 inches deep, be careful of overwatering. Too much water can lead to several issues, including leaf spots and rot. 

When watering, it’s best to direct water to the plant’s base and not directly on the leaves and flowers. If you’re growing zinnias in pots, decide when you should water on how the soil feels. When the ground feels moist, there’s no need to water, but if it feels dry, break out the watering can. 

Fertilizer and Mulch Can Make a Difference with Zinnias

You don’t have to use mulch and fertilizer with zinnias, but they’ll undoubtedly grow better if you do.  Once you have established zinnias, lay down a 2-inch layer of bark or straw mulch. The mulch helps preserve the moisture in the soil, plus it prevents weeds.

If you choose to use fertilizer, you can apply some lightly when your zinnias are still seedlings. Then, you can apply an all-purpose, 5-5-5 fertilizer when the plants start to flower. 

Deadheading Zinnias Frequently Produces More Flowers

Lastly, proper pruning and deadheading will ensure your zinnias blossom beautifully all season long. Once your zinnias are about several inches high, start pruning often to get more branches. You can wait for blooms to wilt before deadheading. But, if you snip the stems as soon as flowers mature, they make lovely additions to bouquets. 

How to Deadhead Zinnias

If you’re not sure how to go about deadheading zinnias, it’s not complicated to do. The most important aspect is that you do it regularly to promote optimum growth. 

Tools You Need for the Job:

  • Pruning shears (or a pair of gardening scissors) 
  • Trash bin or garbage bag
  • Gloves
  • Paper towel or paper plate (if planning to save seeds)
  • Envelope and glass jar (if planning to save seeds)

Ensure your shears are nice and sharp, put on your gloves, and get to work. 

Step 1: Assess Your Zinnia’s Blooms

Inspect your zinnias and search for blooms that appear to be fading or wilting. As they start to lose their vibrancy, this is a sign that it’s time for deadheading. 

If you don’t get to them right away, and the blooms turn brown, don’t worry. Zinnias are a reasonably resilient plant, and waiting too long to deadhead won’t necessarily doom your plant. You can simply pinch off spent blooms with your fingers, but you’ll also likely need to make a few cuts.

Step 2: Make Clean Cuts

It’s essential to use sharp shears so you can create nice, clean cuts every time. When you snip, get as much of the stem as you can. However, there are a few other considerations when you’re deadheading. 

If you want to adjust your zinnias’ height or fullness, where you cut can make a difference. For example, if you want your zinnias to grow low to the ground, cut them further down on the stem. However, if you prefer taller zinnias, make your cuts higher on the stalk. 

Note: If you plant or encourage taller zinnias, place a stake a few inches from them to help with bracing.

If you want your zinnias to grow larger, some people advise waiting till the plant reaches between 8 and 12 inches. Then, when your zinnias fall within this range, cut off the entire top of the plant. The idea is that this encourages more stems to sprout up, ultimately producing more flowers. 

Step 3: Reseed or Save Seeds If Desired

Since zinnias don’t last through the year, dying off with the first frost, decide if you want to reseed them. If so, don’t deadhead the last batch of flowers; let them go to seed instead. You can scatter the seeds throughout the garden.

Alternatively, you can save and store zinnia seeds. When flowers brown and dry, remove them, lay them out on a screen, and let them air out for up to a week. 

Tap the seed head gently to release the seeds (do so over a paper plate or paper towel). Separate all of the seeds from the petals and spread out the seeds. Allow them to dry thoroughly before storing to avoid mold, mildew, etc. 

Finally, place the seeds in a paper envelope, then inside a sealed glass jar. Store them in a cool, dry place, out of direct sunlight. 

More About Zinnias

It’s always nice to know a little something about what you grow in your garden. Here are a few fun facts about the vibrant zinnia:

  • Zinnias are a member of the Asteraceae family, which also includes popular blooms like daisies and sunflowers. 
  • There are over 20 species of zinnias, with dwarf varieties growing as small as 10 inches. Larger varieties can grow up to 4 feet tall. 
  • The zinnia gets its name from German botanist Johann Gottfried Zinn. 
  • You can find zinnias in every color except for blue. 
  • Zinnias represent friendship.
  • Many initially thought zinnias were ugly. Before becoming such a popular bloom, the Spanish called the flower “Mal de Ojos,” which means “sickness of the eye.”  
  • Zinnias can last for about a week after you cut them for an arrangement. 

Related Questions

What are some health benefits of zinnias?

Zinnias, like many plants, feature a few health benefits. Some people use them to make an astringent for the face. 

Others like to use the flowers to create a tea that they believe can help lower cholesterol and improve liver function. Folk medicine employs zinnias in different healing oils to take advantage of their antibacterial and antifungal properties. 

What are good companion plants for zinnias?

Zinnias make excellent companions in vegetable gardens. You can plant them near pretty much any vegetable without consequence and enjoy many benefits. Zinnias attract bees, ladybugs, and other helpful insects, which helps protect vegetables and encourage them to grow.

Stacy Randall

Stacy Randall is a wife, mother, and freelance writer from NOLA that has always had a love for DIY projects, home organization, and making spaces beautiful. Together with her husband, she has been spending the last several years lovingly renovating her grandparent’s former home, making it their own and learning a lot about life along the way.

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