Skip to main content

How to plant dahlia flowers this spring for showy, lush growing season blooms

Everything you need to know about planting and growing dahlias

Pink dahlia
Image used with permission by copyright holder

To brighten up your lush garden landscape with blooms that thrive late into the growing season, you can't go wrong with dahlias. These cheerful statement makers require a careful eye when it comes to watering, but they can truly thrive with a bit of maintenance.

And while dahlia flower care can be moderately challenging, planting these flowers is actually quite easy. If you're wondering how to go from humble tubers to vibrant blooms, we've got you covered with our dahlia guide ahead.

Recommended Videos

Difficulty

Moderate

Duration

1 hour

What You Need

  • Dahlia tubers

  • Soil

  • Low-nitrogen fertilizer

  • Trowel

  • Pruner or shears

  • Organic mulch

Orange dahlia flowers
Timo C. Dinger / Unsplash

What are dahlias?

Hailing from Central America, the Dahlia genus includes roughly 40 flowering plants that belong to the Asteraceae family, which also includes beauties, such as sunflowers and chrysanthemums — in fact, dahlias are very similar to chrysanthemums, except they tend to be smaller. They feature showy flower heads in all sorts of colors, including pink, orange, red, purple, white, and yellow. You'll also find quite a variety of sizes — flowers can be anywhere between 2 and 15 inches wide.

Dahlias typically produce blooms throughout the summer and are perennial in climate zones 8 to 11, where they can stay out in the garden all year round. Naturally favoring warmer climates, they're very frost tender and won't tolerate freezing temperatures.

Pink dahlia
Image used with permission by copyright holder

Different varieties of dahlias

With so many dahlia flower varieties out there, it can be hard to choose when you're trying to make a decision at the garden center. Dahlias come in all kinds of shapes — you can have everything from dinner plate varieties with cupped petals or pompom ones with spherical flower heads. Here are a few special types to keep on your radar as you shop for dahlias.

  • Anemone dahlias: Anemone dahlias feature tubular florets in the center and at least one layer of flat ray petals.

  • Cactus dahlias: Cactus dahlias have long, pointy rays that can be straight or curved.

  • Pompom or ball dahlias: Featuring full double blooms, ball dahlias have a spherical shape with rolled florets that can have flat or rounded tips.

  • Collarette dahlias: Collarette dahlias have an outer ring of flat, overlapping florets and an interior "collar" of smaller florets with an inner disc.

  • Waterlily dahlias: Waterlily dahlias have fully double blooms and feature slightly cupped florets.

  • Dinner plate dahlias: Dinner plate dahlias refer to dahlias with large blooms that measure 8 or more inches in diameter.

Hands planting dahlia flowers in the ground
Image used with permission by copyright holder

When to plant dahlias

The best time to plant dahlias is during spring after the last frost, when the soil is warm enough to accommodate your flowers. While you can get ready-to-go flowers at your local nursery, it's quite easy to start dahlias before they bloom.

Dahlias can grow well from tubers, although you can grow them from seed, too — you'll just need to be in it for the long haul, as it takes anywhere from 100 to 120 days for flowers to grow from seeds. With tubers, dahlias sprout in about six to eight weeks, so plan your planting schedule accordingly. Here's how to start your dahlias from tubers:

Step 1: Make sure the last frost has passed.

Step 2: Find a location that receives partial or full sun.

Step 3: With a trowel to dig dirt, plant your dahlias tubers directly in the ground, in a pot, or in a raised bed of your choice.

If you are growing tubers, keep the eye on the tuber facing upward and place it 4 to 6 inches in the ground. Make sure you use well-draining soil.

Step 4: Plant stakes in the ground to support your plant when it flowers, as dahlias are top-heavy plants.

Implementing stakes (such as bamboo stakes or tomato cages) when you plant your tubers prevents you from damaging established flowers.

Step 5: Keep your plants 2 feet apart.

Watering pink dahlia flowers
David Prahl / Shutterstock

How to care for dahlias

When it comes to care requirements, dahlias share many similarities with chrysanthemums — they appreciate moist soil and partial shade to thrive. For their gorgeous blooms, they also need sufficient fertilizing and watering throughout the growing season. Here’s how to keep your flowers gorgeous and healthy until the next frost.

Step 1: Place your dahlias in a location that gets 6 to 8 hours of full sun a day.

On hot summer days, give your flowers afternoon shade or cover them with a shade cloth.

Step 2: Water your dahlias deeply when the soil dries out — this could be as often as one to three times a week.

You want the water to soak your dahlia's tuber root system, but you don't want your soil to be soggy. Many gardeners prefer using a soaker hose or drip irrigation system for their dahlias.

Step 3: Fertilize your soil about 30 days after planting and continue with a monthly cadence throughout the growing season.

Use a low-nitrogen fertilizer formula (such as a 2-4-4 or 3-9-4 formula) to encourage blooms or stick with an animal feed like cow manure.

Step 4: Hand weed any unwanted plants in their space.

To prevent weeds, you can also use organic mulch to dress your soil.

Step 5: Around the first frost, you can dig up your dahlia tubers and overwinter them somewhere that's frost-free.

Person cutting yellow dahlias
Image used with permission by copyright holder

How do you deadhead dahlias?

With sufficient watering, you will find dahlias blooming from midsummer through fall. As they flower, you can prune and deadhead them to enjoy full-looking flowers. But how do you go about pruning and deadheading your flowers? We've got the answers ahead.

Step 1: Promote side branching and fuller dahlia plants by pruning your dahlias once they develop three sets of leaves and reach about a foot tall.

To prune, pinch the center shoot with clean shears or pruners.

Step 2: Identify spent blooms and deadhead them by cutting off faded flower heads where they meet the stem.

You can also trim off any dead foliage while deadheading, too.

Step 3: To enjoy cut dahlias for your floral arrangements, cut for flowers when the blooms are about 3/4 open.

To promote a stronger plant, cut down to a branching part of your dahlia plant.

Enjoy lush, eye-catching blooms late into the growing season when you plant dahlias during spring or early summer. After planting your tubers, all you have to do is keep an eye out for fertilizing, watering, and deadheading for head-turning flowers. To bring the blossoming beauty into your home, you can even cut your dahlias for stunning flower bouquets to display.

Topics
Stacey Nguyen
Stacey's work has appeared on sites such as POPSUGAR, HelloGiggles, Buzzfeed, The Balance, TripSavvy, and more. When she's…
The top tall flowers for dramatic garden displays
Grow these tall flowers to spice up your garden
A row of kniphofia plants, also called red hot pokers or torch lilies

Gardeners can design their outdoor spaces in a plethora of ways. From rowdy wildflower gardens to carpets of tiny flowers, there’s a garden design for everyone. If you want your garden to have a dramatic impact on your guests, then plants of varied heights are your friend. Smaller plants at the front leading up to tall flowers in the back make for quite the display. Not just any tall plant will do, though. These are some of our favorite tall flowers for drama and pizazz, and they’re sure to captivate an audience on their own or as part of an ensemble. Not to mention, they’re all fairly easy to grow.
Torch lily

Kniphofia flowers have many common names, including torch lilies and red hot pokers. Both names are accurate descriptions, as these flowers strongly resemble fiery torches or red hot metal. They have tall, straight stems topped with small red, orange, and yellow flowers set in a cone or bottlebrush shape.

Read more
Hollyhock growing guide: Everything you need to know
Add hollyhocks to your garden this year
White hollyhock flowers against a stone wall

Hollyhocks, known for their tall flower spikes and large, vibrant flowers, make a gorgeous addition to most gardens. Pollinators love them, and they come in a wide array of lovely colors. While they’re commonly planted alongside structures or as the main feature in a garden bed, they’re also quite versatile. If you want to add hollyhocks to your garden this spring or summer, then this hollyhock growing guide is the perfect place to start! Here’s everything you need to know to grow these flowers successfully.
Planting hollyhocks

If you’re growing hollyhocks from seeds, you can start them in late spring. Older hollyhocks can be planted in late summer or early fall. Plant your hollyhocks in rich, well-draining soil for the healthiest plants and best flowers. They can tolerate other soil types, but they thrive in loamy soil that has plenty of organic matter. Hollyhock plants grow quite tall, and they need plenty of nutrients to fuel that growth.

Read more
5 incredible plants for rock gardens: Consider these options
Start your rock garden with these fun plants
Stonecrop in a rock garden

Rocks gardens are a simple way to design a garden with visual interest, especially if you live in an area where keeping a lawn full of grass alive is challenging. Rocks gardens are often home to drought-tolerant plants, as they most commonly mimic desert or mountainous environments. Easy to set up and simple to maintain, the only question left is what will you plant in it? There are many options, but if you want to know where to start, then you’re in the right place! This list of a few of our favorite plants for rock gardens will help you start to plan your very own gorgeous rock garden.
What types of plants grow best in rock gardens?

Rock gardens are best suited for drought-tolerant plants that can grow in poor, rocky soil. While you can grow other types of plants in a rock garden, it will take more effort on your part. Mixing compost into soil that’s full of rocks can be tricky, for example, so growing plants that need rich soil is more challenging.

Read more