All About Dahlias & How To Choose The Right Plant

There are not enough superlatives to describe the way Dahlia flowers turn into glowing orbs of color when the sun shines through the petals. Or the sheer delight of taking a garden tour and happening upon a huge Dahlia bloom as big as your head. With their picture-perfect blooms, Dahlias are taking the gardening world by storm. Learn more about these wonderful plants and which are best for your garden.

Dig In With Dahlias:

• Where Do Dahlias Come From?
• What Is A Dahlia Tuber?
• Where Can You Plant Dahlias?
• Which Dahlias Should I Grow?
• Learn More About Dahlias

Dahlias are native to Mexico and South America, and they have a long and intriguing history of capturing the heart of people around the world. Indigenous people grew Dahlia tubers as a source of food and medicine.

Dahlias, or acoctili as they were originally known, were documented by the Spanish in the 1500s, and eventually traveled to Europe by the 1700s. In time, they even charmed Marie Antoinette and became known as a symbol of commitment, dignity, and elegance.

Over the centuries, plant breeders have developed thousands of variations of these beautiful blooms.

Dahlias grow from tubers, which are swollen underground stems. They sprout “eyes,” which develop into stems and flower stalks. Dahlia tuber clusters look like an upside-down bouquet of sweet potatoes. At the top is the old stalk from the previous year’s growth. The eyes are usually located at the top of the tubers, closest to the old stalk.

You can divide dahlia plants that are more than a year old by cutting apart the tuber clump. Each separated tuber needs to have an eye in order to sprout and grow when planted.

Planting Zones

Dahlias can be grown in all zones in the United States. Dahlias are perennial, growing back from the same tuberous root system year after year. However, they are only cold hardy in zones 8-11, and are generally only left in the ground to overwinter in climates where there is no winter freeze. In cooler zones, they can be grown as annuals, or the tubers can be dug and stored for winter and re-planted in spring.

Growing Requirements

Choose a location with good light. Dahlias require full sun, with 6 or more hours of sunlight daily. Less sun will result in decreased flowering. They need rich, but well-drained soil. They perform best in temperate climates, and in the hottest climates, they should be grown in areas where they can get relief from the hottest afternoon sun. 

To learn more about how to plant Dahlia tubers, see our guide: How To Grow Dahlias

Depending on the Dahlia variety that you choose, there can be a wide range of flower sizes! Dinner Plate Dahlia flowers are the largest, and Pompon Dahlia flowers are the smallest - and there are several in between. To learn more about each Dahlia type, read our article: Discovering Dahlia Flower Forms: Find Your Favorite Flower.

Discovering Dahlia Flower Forms: Find Your Favorite Flower

Dazzling Dahlias In Every Color: Choose Your Favorite Hue

How To Grow Dahlias