Growing Dahlias

by High Country Gardens

Cactus Dahlia with Butterfly
Cactus Dahlia with Butterfly

Growing Dahlias is easy. There are so many interesting and beautiful variations--once you start, it may be hard to stop planting more! They're almost addicting to grow, especially when you consider the ease of planting and the big return: months of spectacular blooms.

Native to Mexico, Dahlias are loved all over the world. We like to think of them as our tropical cousins brightening up our summer gardens with a fiesta of color.

How To Growing Dahlias with Sunflowers results in a cheery look.
Bishop of Llandaff Dahlias paired with annual Sunflowers

Use as a dramatic background for a perennial bed or to fill in bare spots in a new garden bed. Many people create a Dahlia garden to enjoy the splendor of flowers as they interact with each other and to use for creating lovely bouquets. Dahlias will add drama to any setting.

Growing Dahlias: Tips for Planting Dahlias

  • Grow Dahlias in full sun and compost-enriched, well-drained soil.
  • Plant the Dahlia tubers in the spring when the danger of frost is past (soil should be 55-60 degrees).
  • They are heavy feeders, so be sure to add both compost and an organic fertilizer (some gardeners recommend a low nitrogen fertilizer (3-8-8 or similar).
  • They also prefer a slightly acidic soil (around 6.5), amending the soil ahead of planting may be a good idea.
  • Once you’ve gotten your soil ready, working to a depth of 6 inches, the hard work is over. Plant 1-3 tubers per square foot minimum, just 1-2 inches deep.
  • Lay Dahlia tubers on their side with the eyes facing up. If your soil is already moist, no need to water initially, otherwise water.
  • It’s best to keep the tubers on the dry side until you see sprouts, then water deeply and regularly.
Grow Dahlias - Dahlia Tubers
Plant Dahlia tubers, stem side up, at a depth of 1-2 inches, in spring after danger of frost has past.

Dahlia Parkland Glory
Dahlia Parkland Glory

Growing Dahlias: Staking Tips

Dahlias can be susceptible to wind, so keeping them somewhat protected is advised. Big Dahlias like ‘Parkland Glory’ need a wall or a couple of sturdy stakes to support them as they grow. The blooms are heavy and the stems can be somewhat delicate.

So plant two sturdy stakes when you plant your tubers. This way you can tie it to the stakes as it grows giving it plenty of support. The leaves of the plant will hide your stakes.

As your plants grow they will produce many buds. If you want really big blooms, you could pinch lateral (side of the stem) buds off, letting the plant put its energy into fewer blooms. But, lots of flowers are fun, so no pinching is a fine way to go too. Fertilize monthly up until mid-August. When the blooms are spent, deadhead the plant to keep flowers coming.

Great as cut flowers, cut the stems long (12-18 inches) to stimulate new growth and of course, new flowers.

Growing Dahlias: After Season Care

  • Hardy in zones 8-10, no special care is needed for an easy-to-grow perennial plant.
  • In colder areas (zones 3-7) dig or pull the roots, just before or after, the first frost.
  • Cut off the stems, dig around the plant leaving room for the tubers that grow out from the stem.
  • Clean the tubers, dry them and store them in a paper bag with sawdust.
  • Alternatively place clean, dry, healthy tubers in a cardboard box or bushel basket on a bed of vermiculite, cover with an inch or two, leaving the stem exposed.
  • Store in a dark, cool place until spring planting time.
  • TIP: Zones 3-7: Save your packaging when your Dahlias arrive so that you can easily label your Dahlia tubers when you dig them in the fall.
  • Keeping the photo with the tubers will remind you what you are planting next spring.
  • Over the years, the tubers will multiply, giving you more to plant and share with friends. If digging and saving the tubers sounds like too much work, you can just treat them as annuals and plant fresh tubers every spring.
Dahlia Firepot
Fire Pot Dahlia

Growing Dahlias: Fun Facts

Traditionally in Mexico, the tubers were prized by native people for their large sweet potato-like tubers. It is still known as one of the native foods of Oaxacan cuisine.

Nurtured in the fabulous gardens of the Aztec king, Montezuma, Cortez probably brought many varieties back to Spain.

Declared the national flower of Mexico in 1963, Dahlias express the color, variety and joy of their native land.

Bring some summer cheer into your garden with Dahlias!

  1. Dinnerplate Dahlia Cambridge, Yellow Dahlia

    Dinner Plate Dahlia ‘Cambridge’ has 8-10 inch double yellow flowers stippled and streaked with red, resembling a giant, sunny bloom spun through with red paint. This plant grows ...

    Learn More
    Cambridge Dinnerplate Dahlia Cambridge Dinnerplate Dahlia Dinnerplate Dahlia Cambridge
    Regular Price $17.99 Sale $14.39
    Per Bag of 3
    You save: 20%

    Dinner Plate Dahlia ‘Cambridge’ has 8-10 inch double yellow flowers stippled and streaked with red, resembling a giant, sunny bloom spun through with red paint. This plant grows to a stately 36-40 inches, making it a great choice for mid-summer color where height is desired. Plant tubers in the spring in compost enriched garden soil once the soil has warmed. Dahlias need full sun (at least 6 hours/day). Enjoy flowers from mid-summer through fall. Great as cut flowers, pollinators love them too. Hardy in zones 8-10. Grow as annuals elsewhere.

    Learn More

© All articles are copyrighted by High Country Gardens. Republishing an entire High Country Gardens blog post or article is prohibited without written permission. Please feel free to share a short excerpt with a link back to the article on social media websites, such as Facebook and Pinterest.