How To Grow Dahlias

Growing Dahlias is easy. There are so many interesting and beautiful variations. They're almost addicting to grow, especially when you consider the ease of planting and the big return with months of spectacular blooms.

Native to Mexico, Dahlias are loved all over the world. We love to see them brightening up our summer gardens with a fiesta of color. Dahlias will add drama to any setting. Use them 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 cut flower bouquets. Follow our guide for simple planting and care instructions. Once you start growing them, it may be hard to stop! 

Tips For Planting Dahlias

Plant the Dahlia tubers in the spring when the danger of frost is past (soil should be 55-60 degrees).

Light: Grow Dahlias in full sun

Soil: Grow Dahlias in compost-enriched, well-drained soil. 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). A soil test can confirm if amending the soil ahead of planting may be a good idea.

TIP: Save your packaging when your Dahlias arrive so that you can easily label your Dahlia tubers when you dig them in the fall. (See After Season Care below.)

How To Plant Dahlias

1. Once you’ve gotten your soil ready, working to a depth of 6-12 inches, the hard work is over.
2. Following the recommendations for spacing on your packaging, dig holes for your tubers. For larger varieties, we recommend staking to support heavy flowers. See Staking Tips below.
3. Plant 1-3 tubers per square foot minimum, just 1-2 inches deep. Lay Dahlia tubers on their side with the eyes facing up.
4. If your soil is already moist, no need to water initially, otherwise, water the freshly planted tubers.
5. It’s best to keep the tubers on the dry side until you see sprouts, then water deeply and regularly.

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.

Growing Dahlia Flowers

As your plants grow they will produce many buds, typically with a large central bud and smaller side buds (lateral buds)

To encourage extra large blooms, you can remove lateral (side of the stem) buds, leaving the central bud, and allowing the plant to focus its energy on that one large flower.

Lots of flowers are fun, so no pinching is a fine way to go too. Fertilize monthly up until mid-August with a low-or-no-nitrogen fertilizer.

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

After Season Care For Dahlia Tubers

Over the years, the tubers will multiply, giving you more to plant and share with friends. 

Dahlias are hardy in zones 8-10, so no special care is needed for an easy-to-grow perennial plant in these warm zones.

In colder areas, zones 3-7, Dahlia tubers will not survive the winter. So, you'll need to dig or pull the roots, just before or after, the first frost. (Or, if digging and saving the tubers sounds like too much work, you can just treat them as annuals and plant fresh tubers every spring.)