Dahlias are mesmerizingly beautiful flowers that bloom in every color of the rainbow.

These stunning plants are grown from tubers, typically planted in late spring. Learn all about planting, nurturing, and enjoying these dazzling floral wonders.

About Dahlia Flowers

Choosing a favorite dahlia is as delightful as selecting a jewel from a treasure chest. These flowers range from petite 2-inch pompoms to massive 15-inch “dinner plates.” Most varieties grow between 4 and 5 feet tall. Their colors span a wide spectrum, including white, yellow, orange, pink, dark pink, red, lavender, purple, black, and an array of blended, variegated, or bicolored hues.

Dahlias belong to the genus Dahlia within the Asteraceae family. Their tubers are planted in late spring (around May) and bloom from July until the first frosts of autumn. Perfect for garden borders and as cut flowers, dahlias can even complement vegetable gardens when planted along the edges.

Are Dahlias Perennials or Annuals?

Dahlias are tender perennials native to the warm climates of Mexico. In regions with hardiness zones of 8 and higher, they are perennials. However, in colder zones (7 and below), they are treated as annuals.

Overwintering Dahlias

In colder areas, tubers can be dug up after the first frost and stored in a cool, dry place until the next planting season. This method ensures their survival and readiness for replanting in spring.

Planting Dahlias

Dahlias thrive with 6 to 8 hours of direct sunlight daily, especially morning sunlight. They prefer rich, well-drained soil with a pH between 6.0 and 7.5. When planting, the mature size of the variety should be considered.

When to Plant

Plant when soil temperatures reach 60°F (15°C) and frost danger has passed.

Tubers can be started indoors in containers a month prior to the outdoor planting season to extend their growing period.

How to Plant

Dear Lykkers, select tubers with firm textures and visible pink “eyes” or buds.

Dig 6- to 8-inch deep holes and mix compost or bonemeal into the planting soil.

Place the tubers with their growing points facing upward, and cover them with 2 to 3 inches of soil.

Water only after sprouts emerge to prevent rot.

Stake taller varieties to support growth and prevent bending.

How to Plant Dahlia Tubers From Start to Finish

Video by Epic Gardening

Growing Dahlias in Containers

Medium to dwarf varieties thrive in well-drained containers. A 12x12-inch-pot is typically sufficient.

Container Tips

Use a soilless mix with moisture-retaining crystals.

Follow planting depth guidelines and water sparingly until sprouts appear.

Fertilize regularly throughout summer and add soil as needed to cover exposed roots.

Maintaining Dahlias

Once established, dahlias should be watered 2 to 3 times weekly, increasing frequency during hot weather. Large blooms may require additional care during rain or wind.

Fertilization

A low-nitrogen fertilizer, such as 5-10-10, promotes healthy blooms. Fertilize every 3 to 4 weeks until early autumn.

Pruning and Deadheading

Pinch the center branch when plants reach 1 foot tall to encourage bushier growth.

Deadhead spent flowers to prolong blooming.

For larger blooms, remove smaller buds in a cluster to focus energy on fewer, larger flowers.

Harvesting Dahlias

Regular cutting encourages more blooms. Stems should be cut in the morning and placed in cool water immediately. For longer vase life, keep arrangements in a cool spot and refresh the water daily.

With proper care, dahlias bring vibrant beauty to gardens and homes throughout the growing season.