You Should Deadhead Your Zinnias Right Now for Better Blooms, a Gardener Says—Here’s How

Zinnias are easy-growing summer flowers that shine in cutting gardens, container plantings, and ornamental beds alike. These colorful, versatile blooms are available in a variety of shades, including hues of orange, yellow, red, purple, pink, and white.

But what about when those flowers are spent? Should you deadhead zinnias, or leave faded flowers on the plant? Here’s how to deadhead zinnias to keep your garden looking tidy and promote fresh blooms all summer long.

Should You Deadhead Zinnias?

Short answer: Yes, it’s a good idea to deadhead your zinnias. Removing spent flowers from your zinnia plants can help promote reblooming and extend bloom time.

Leaving that dying material on the plant will take up nutrients it could otherwise use to rebloom. By removing faded stems, you’re allowing the plant to expend its energy on creating new flowers rather than growing seeds from the spent ones.

Many flowers, including geraniums, yarrow, tickseed, garden phlox, bee balm, and zinnias, benefit from deadheading.

Deadheading leads to more colorful blooms for you and the pollinators in your garden to enjoy. It keeps plantings looking healthy and strengthens their growth.

However, if you’re hoping to save zinnia seeds to plant next year, you’ll want to leave some of your flowers on the plant to fully develop seeds after the blooms fade. Though zinnias are annuals, leaving seed heads to develop on the plant late in the season could lead to reseeded plants the following spring.

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When to Deadhead Zinnias

You can begin deadheading zinnias when you first see flowers turn brown after plants come into their first bloom, typically late spring or early summer depending on your growing zone.

It’s a good idea to deadhead regularly as spent blossoms appear. In addition to keeping your zinnias looking neat and promoting more growth, it’s a good way to inspect plantings for any other issues, such as pests or powdery mildew.

Zinnias will continue blooming into fall, which is a good time to stop deadheading for the year. Instead, leave faded flowers on the plant to develop seeds before the first frost. Those seeds can provide a valuable food source for birds over the winter.

How to Deadhead Zinnias

Deadheading zinnias is a simple task you can accomplish with a pair of sharp, sterilized scissors or pruners. Here’s how to do it.

1. Look for spent flowers on your zinnia plants. Unlike the fresh, colorful flowers, they’ll be brown and dry after they fade.
2. Make a cut in the stem below the flower head and right above a set of leaves. This will help encourage full, bushy growth as well as new blooms.
3. Collect spent flower heads to discard in the compost or trash.

Pinching vs. Deadheading Zinnias

The terms “pinching” and “deadheading” are sometimes used interchangeably, but these plant care techniques differ in how, why, and when they’re used. Zinnias don’t require pinching, but they do benefit from deadheading when flowers are spent.

Pinching is a form of pruning, often done when plants are young, before flower buds have set. The purpose of pinching is to encourage full, bushy growth rather than tall, leggy plants.

The very end of the plant’s stem contains auxin, a hormone that makes plants grow tall and straight. Removing that tip by pinching it with your fingers or cutting it back with shears removes the hormone and encourages side branching rather than a single main stem.

Some garden plants that benefit from pinching when young are marigolds, coleus, snapdragons, and herbs like basil, oregano, and thyme.