Dahlia vs. Zinnia: Flower Comparison (2024)

You’ve probably heard about dahlias and zinnias and maybe even seen some of the beautiful blooms in your neighborhood. But do you understand what makes each one different from the others? Let’s take a closer look at these flowers’ similarities and differences.

While there are wide varieties of dahlias and zinnias, here we’ll focus on just two common types: dahlias and zinnias. Dahlias come in various colors: reds, oranges, yellows, pinks, purples, greens, whites, blues, browns, and black. They grow into large plants up to three feet tall. While most people think of dahlias as annuals, they bloom every summer.

Zinnias are another popular flower in various colors, including orange, yellow, pink, purple, blue, white, and lavender. They grow into small plants that reach about 18 inches high. Like dahlias, zinnias bloom in the summertime.

There are several critical differences between dahlias and zinnias. First, while dahlias require full sun, zinnias prefer partial shade. Second, dahlias generally grow into larger plants than zinnias. Third, dahlias produce smaller blooms than zinnias. Fourth, dahlias tend to be less expensive than zinnias. And finally, while dahlias and zinnias are easy to grow, zinnias are much easier to care for than dahlias.

However, some zinnia varieties, such as the “Profusion” series, can look similar to dahlias with their densely layered petals and vibrant colors.

So now that you know more about these two flowers let’s dig deeper into how to choose the best ones for your garden.

Variation in Bloom Size

Zinnias and Dahlias come in various sizes, from small to large. But which one is the biggest?

The size difference between Dahlia and Zinnia is significant, with Dahlias typically larger than Zinnias. A daffodil (Dahlia) usually ranges in size from 3 to 14 inches tall, while a zinnia will be smaller, generally reaching heights of 2-7 inches. However, there are exceptions to this rule – some dahlias can grow up to 18 inches tall!

One reason for the big size difference between Dahlias and Zinnias may be that zinnias tend to originate from cooler climates where taller plants are more common. This might also explain why zinnias often have darker colors and thicker petals than dahlias.

Differ in Bloom Shapes

When selecting your favorite flowers, it’s important to consider their shapes too. Dahlias and zinnia differ significantly in shape. Dahlias are long-stemmed, tubular, cylindrical-shaped flowers. Their centers are cone-like, tapering down towards the bottom. The flowers are usually arranged around an elongated stalk called a rachis.

In contrast, Zinnias have round or oval faces, with the center opening facing upward. Unlike Dahlias, which are open-faced, Zinnias often sport tight little buds when they first emerge each spring. These buds then burst open into showy blooms. In addition, Zinnias are shorter than Dahlias, measuring only 1 to 4 inches tall.

The shape and color patterns of the flowers make them visually distinctive. But what exactly makes them so attractive? It turns out that it has everything to do with the arrangement of their parts.

Flowers Arrangement

Dahlia and Zinnia flowers are distinguished by their different arrangements. While Dahlias are often grown alone, adding color and interest to areas within your yard, Zinnias are commonly grouped, creating a colorful display that draws attention.

A single Zinnia plant can create a beautiful bouquet if properly cared for. When arranging Zinnia blooms, remember that the center should point up. Also, try not to cover the entire face of the blossom, leaving at least half of its surface exposed. Finally, look for Zinnias with wide open faces; these are the most attractive varieties.

Differ in Color Patterns

Color plays an integral part in determining beauty among Dahlia and Zinnias. Dahlia blossoms are traditionally white, pink, red, or purple. While other hues exist, these four dominate the market.

On the other hand, Zinnias offers a wider selection of color options. From deep reds and purples to pastel pinks and yellows to soft greens, blues, and even oranges, Zinnias have plenty to choose from.

Zinnia blossoms don’t represent only blue, brown, and black. Going with zinnias can be the ideal option if you want to have more color choices. Both create stunning blooms and either method. You can have many different hues of blossom.

Height Differences

When comparing dahlias and zinnias, height variations are also taken into account. Typically, zinnia plants reach heights of six inches to fifty inches. Plants that grow dahlias can grow considerably taller. Most of these plants grow to at least one foot, but some can reach six feet. You will obtain huge flowers if you buy one of the taller dahlia plant species. These blossoms will be significantly bigger than anything zinnia plants can produce. Dahlia plants can satisfy anyone looking for the largest blooms imaginable. This doesn’t negate that the zinnia plant is striking and lovely in its own right.

Different Hardiness Zone

In various environments, both dahlia and zinnia will thrive. Despite the substantial overlap, the USDA does not recommend planting these two plants in the same zone.

Specifically, dahlia plants should be grown in USDA zones 8 through 10. If you live outside of these zones, it will be difficult to grow these flowers outside of a greenhouse.

Zinnias can thrive in a wider range of USDA hardiness zones. Plants of the genus Zinnia can be grown in USDA zones 2 through 11.

Consequently, zinnias will thrive in the same climates as dahlias. However, dahlia plants cannot thrive in most climate zones, whereas zinnia thrives.

Flower Scent

Dahlias have a sweet smell like Jasmine that can vary depending on the type and growing conditions, while Zinnias are generally considered completely scentless. Both plants offer stunning colors and beautiful blooms, but they may not be the best choice if you’re looking for a strong fragrance.

Which Flower is Better?

This question doesn’t have a solution. Depending on what you’re after, you could want to grow dahlias or zinnias in your garden.

Dahlia plants can grow taller and have greater flowers. There will be more color options for zinnias.

Both of these plants share many characteristics, but they also differ greatly. Even the shapes of the flowers are distinct when you look at them closely.

Many people will find owning zinnias to be more practical. They can grow successfully in USDA zones 2 through 11, allowing them to be planted in many locations where dahlias cannot.

Use this knowledge to choose the ideal flower for your garden bed. You might even be able to grow both in your yard if you reside in the correct USDA zone.