When Do Dahlias Bloom? – An Overview

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Last Updated on January 26, 2022 by Cinthia

If you are a new gardener, you may be wondering when do dahlias bloom and how long their bloom will last; wonder no more. 

Dahlias are one of the most popular summer-blooming flower buds that are loved by gardeners. Most people enjoy growing them because of their easy maintenance and their large assortment of colors and bloom shapes to choose from.

Facts about Dahlias 

  • Dahlias are native to Mexico, Colombia, and Central America
  • These flowers grow from small tubers 
  • They thrive in warm weather though not extremely hot climates of Texas or South Florida
  • Dahlias planting season is spring
  • They have over 20,000 cultivars from 9 flower classifications  
  • Dahlias are a genus of tuberous plants that are members of the Asteraceae  family
  • These flowers are closely related to daisies, sunflowers, zinnia, and chrysanthemum
  • Dahlia flowers range in size from 2-inch lollipop size pompoms to 15-inch dinner plate size blooms
  • They can grow 4 to 5 feet tall
  • They are winter hardy in zones 8 to 11
Facts about Dahlias

When Do Dahlias Bloom?  

  1. Plant dahlias tubers in the springtime when the ground is warm enough about the same time you would plant your vegetable garden.  
  2. Plant them in an area that gets full sun for about 6 to 8 hours of direct sunlight.  
  3. At the beginning of summer, they will start to bloom and provide you with an abundance of flowers and colors.  
  4. You can enjoy cutting them and placing them in vases indoors for a bright home throughout summer. Cut dahlias will last up to 5 days when cut and treated.
  5. The more you cut a dahlia plant, the more it will bloom.

Choosing Dahlias for Your Garden 

Choosing dahlias to grow is much more difficult than actually growing them. These flowers come in a variety of types. Horticulturists have divided them into 10 classifications. These classifications have numerous subcategories and distinctions. You can classify dahlias into 3 broad groups – Large, Medium, and small. 

  • Large Dahlias. They range from 3 to 4 feet tall. They are also known as dinner plate dahlias for their 10-12 inch diameter double flowers. Large dahlias are best grown at the back together with other large perennials. They put on a stunning late summer and early fall show and require support to withstand summer rain and winds. Use whimsical spiral support or thick bamboo stakes.

  • Medium Dahlias. These are also known as border dahlias. They are compact 1 to 2 feet tall. They are best planted in the front of a perennial bed, and you can mix them with other late-blooming perennials like asters and phlox. These border dahlias can also grow in containers. You can choose cactus flowered dahlias that have distinctive rolled petals.   
  • Small Dahlias. These are perfect for window boxes. Small dahlias are 10 – 20 inch plants that bloom for a long time and remain fairly compact. You can have them at the edge of a border or in planters and pots. 

Learn more about Flowers Blooming Season:

How to Grow Dahlias 

Now that you know what type you want to grow, let’s learn how to plant them. 

  • Soil – Dahlias thrive in well-drained soil and a sunny area. They like warm weather and do not tolerate frost.  To plant dahlias, dig a 6 to 12-inch deep hole and add compost to the soil. If your soil is poor in drainage, mix it with some fine gravel. Fill the hole with soil halfway and plant the tubers 2 to 4 inches deep.

Professional Grower Mix Soil Fast Draining Pre-Mixed Coarse Blend

  • When to Plant – Plant your tubers after the last frost date when the soil is warm.  If you live in a cold area and want to start planting early, you can put each tuber in its own pot 2 to 4 weeks before your last frost date. Once they have sprouted, place the pots under grow lights or in front of a sunny window. Once the frost clears, transplant them gently into the garden location you have prepared in advance. Make sure the soil is warm enough not cold from the frost. It will be wise to give it some time to warm from the frost.
  • Where to Plant – Make sure the tubers are 1 to 3 feet apart depending on the variety. You will notice that growth will begin 14 to 20 days after planting. 

Remember to support tall varieties to keep them from falling over. Their stems need help to be able to carry the flower once it blooms. 

Dahlia Blooming Season

Besides the question when do dahlias bloom, you have learned more about choosing the type and growing these flowers. It’s your time to plant your flowers and enjoy their bloom in the summer season. Nothing like a full garden full of blooms during summer, or beautiful cut flowers in your vase; they attract good vibes and a happy home.


When Do Dahlias Bloom?

The time of year when you should be planting your dahlias is very important, and this can determine whether or not you will get a good harvest. The best time to plant Dahlias in the fall is during the cooler months, as their growing season will have ended by then, but they can be planted in spring and summer if you live in a warmer area.

Dahlias bloom from late spring to early summer. They bloom in succession, each flower maturing and opening on a stalk before the next flower blooms. The number of petals on a dahlia flower is determined by the variety; some have more petals than others.

When Do Dahlias Bloom?

The short answer is yes. They do, and they’re great! But the longer answer is that there are a number of different species, each with different needs. We’ll tell you what to expect in terms of care requirements and growth rates for each, as well as how to make sure they’re happy all season long.

How long do dahlias bloom for?

Dahlias are very long-lived plants. In fact, many will flower for more than 30 years. Dahlias have a tendency to bloom when it’s warm and dry, so they may not be at their best if you live in a rainy climate. There are two main types of dahlias: winter-hardy, and spring-flowering.

Do dahlias keep blooming all summer??

Dahlias have a short blooming season and will start to fade soon after flowering if the weather gets cold.

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