What is the Difference Between Dahlia and Zinnia

Dahlias and Zinnias are colorful, popular flowers that belong to the sunflower family. Both plants are easy to grow and make beautiful additions to any garden.

What is the difference between dahlia and zinnia? Dahlias are perennials that grow from tubers while zinnias are annuals that grow from seeds.

Key Areas Covered

1. What is Dahlia  
      – Definition, Features
2. What is Zinnia
      – Definition, Features
3. Similarities Between Dahlia and Zinnia
      – Outline of Common Features
4. Difference Between Dahlia and Zinnia
      – Comparison of Key Differences
5. FAQ: Dahlia and Zinnia
      – Answers to Frequently Asked Questions

Key Terms

Dahlia, Flowers, Zinnia

What is Dahlia

Dahlias are beautiful flowering plants from the Asteraceae family. They are related to sunflowers, daisies, and chrysanthemums. With 49 different species, dahlias come in nearly every color except blue. They have a variety of flower shapes and sizes, including spherical ball shapes, flat waterlily types, and spiky cactus forms. Dahlias can grow between 12 to 72 inches tall, and some decorative varieties can have large blooms up to 10 inches in diameter.
These plants have tuberous roots. Dahlias are perennials, meaning they come back year after year. 

Dahlias need a bit of extra care, especially when it comes to water. They require consistent moisture but need well-draining soil to avoid sogginess. They thrive in full sunlight and prefer rich, slightly acidic soil. In warmer areas (USDA zones 8 to 11), dahlias are perennials, but in colder zones, you’ll need to dig up the tubers in the fall and replant them in the spring. Instead of seeds, dahlias are grown from tubers, which makes propagation a little more work.

What is Zinnia

Zinnias are hardy, vibrant flowers that belong to the genus Zinnia. Zinnias can grow between 8 to 48 inches tall and have smaller blooms compared to dahlias. Their flowers come in a variety of forms, including single, double, and semi-double, offering a beautiful spectrum of colors like red, orange, yellow, pink, purple, and even green.

Zinnias thrive in full sunlight, and need at least 6 hours of sun each day. They grow best in well-drained, fertile soil with a neutral to slightly acidic pH. Regular watering is important to keep the soil evenly moist. This helps them flourish throughout the season.

Since zinnias are annuals, they bloom for a single growing season, but they self-seed. This makes them a low-maintenance choice for future gardens. 

Similarities Between Dahlia and Zinnia

1. Both belong to the Asteraceae (sunflower) family.
2. Both plants thrive in full sun.
3. They have vibrant blooms in a wide range of colors.
4. Both have different flower forms, including single and double blooms.
5. They are popular for ornamental gardening.
6. Both prefer well-draining, fertile soil.

Difference Between Dahlia and Zinnia

Definition 

• Dahlia is a bushy, tuberous perennial plant native to Mexico and Central America, known for its large, colorful flowers. Zinnia, on the other hand, is a genus of plants from the sunflower family, native to dry grasslands from the Southwestern U.S. to South America.

Height

• Dahlia can grow taller, up to 72 inches while zinnia is shorter, usually between 8 to 48 inches.

Bloom Size

• Dahlia has larger, showier blooms, with some reaching up to 10 inches, whereas zinnia has smaller blooms compared to dahlias.

Bloom Types

• Dahlia has a wide variety of bloom shapes like ball, pompon, and waterlily while common bloom types in zinnia are single, semi-double, and double.

Growth

• Dahlia grows from tubers whereas zinnia grows from seeds.

Lifespan

• Dahlias are perennial plants while zinnias are annual plants.

Watering

• Dahlia needs consistent moisture but not soggy soil while zinnia needs regular, even moisture but is less demanding than dahlias.

Soil

• Dahlia prefers rich, well-draining soil that is slightly acidic, whereas zinnia does well in most soils but prefers well-drained, fertile soil.

FAQ: Dahlia and Zinnia

1. Are zinnia and dahlia related?

Yes, zinnia and dahlia are related. Both belong to the sunflower family, Asteraceae and are known for their bright, colorful flowers.

2. How do I identify dahlias?

You can identify dahlias by their large, colorful blooms and tuberous roots. Single dahlias have daisy-like flowers with one row of petals around a different-colored center. Peony-flowered dahlias have two or more rows of petals around the center.

3. Do zinnias need full sun?

Zinnias need at least 6 hours of full sun each day to bloom their best. They thrive in bright sunlight and may not grow well in shady areas.

4. Do dahlias like sun or shade?

Dahlias grow best with lots of sun, especially in cooler places where they need long, sunny days. In hotter areas, they can handle some shade in the afternoon to avoid too much heat. If they don’t get enough sun, they might have fewer flowers and grow slower. 

5. Are there two types of dahlias?

Yes, there are many types of dahlias, but two common types are single dahlias and peony-flowered dahlias. Single dahlias have one row of petals around the center, while peony-flowered dahlias have two or more rows of petals. 

Reference:

1. “Dahlia.” Wikipedia. Wikipedia Foundation.

2. “Zinnia.” Wikipedia. Wikipedia Foundation.

Image Courtesy:

1. “Spectacular garden flower – Dahlia” By Shiv’s fotografia – Own work (CC BY-SA 4.0) via Commons Wikimedia

2. “Close-Up Photography of Zinnia Flowers” (CC0) via Pexels