With their intense color, strength, and ability to keep flowering until the first frosts, dahlias are easy to grow and bring life to your garden. Dahlias like well-balanced and composted soil, and full sun. With 42 different species and thousands of cultivars, dahlias offer plenty of variety. Variations in color, flower form, size, and foliage make it easy to find one youll love.
Generally winter hardy in zones 7-10, and tubers can stay in the ground. In colder zones, tubers can be dug up, stored for winter and re-planted in spring, after all danger of frost has passed. (See below for storage tips.)
1 to 6 feet tall, and 1 to 3 feet wide depending on the variety; border dahlias range 15 to 20 inches tall.
According to Frances Palmer, well-known potter and dahlia enthusiast, a good planting time for tubers is May. Here are her recommendations for planting:
If you live in a cold climate and want to get a head start, tubers can be started inside 6 weeks before moving them out to the garden. Plant them in pots with potting soil and provide plenty of light and water. When the ground temperature in your garden reaches 60°F it is safe to transplant your dahlias.
Dahlias are one of the most popular flowers for gardens because of their incredible diversity and vibrant colors. With so many sizes shapes and hues to choose from dahlias allow you to get really creative with your garden design.
A beautifully designed dahlia garden can take your landscape to the next level and become a true focal point. The key is thoughtfully planning the layout and combinations.
In this article, we’ll explore some of the most stunning dahlia garden design ideas to inspire your own colorful oasis. Let’s look at how to use dahlias as accents, borders, mass plantings and more.
Plan Out Your Dahlia Garden
When designing a dahlia garden it’s important to start with a plan for optimal results. Here are some tips
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Decide on a location – Dahlias need full sun, so choose a sunny spot that gets at least 6 hours of direct light daily.
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Select varieties – With so many types, it’s fun to mix heights, colors and bloom forms for diversity. Be sure to check mature sizes so taller varieties don’t overshadow smaller ones.
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Space plants properly – Refer to plant tags or descriptions for recommended spacing. Crowding causes air circulation issues.
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Incorporate other plants – For added interest use companion plants like annuals grasses and shrubs.
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Map out bed shape – Linear beds, sweeping curves or geometric patterns all create structure.
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Include vertical elements – Trellises, arbors, obelisks and supports add height and drama.
15 Beautiful Dahlia Garden Designs
- Dahlia Border
A simple yet impactful way to showcase dahlias is mass planting them in borders along fences, sidewalks or walls. Use repeating colors or a gradation of hues.
- Oversize Island Bed
For big impact, dedicate a large round or kidney-shaped bed solely to dahlias. Highlight one stunning variety or mix many.
- Geometric Dahlia Bed
Think outside the box by arranging dahlias in creative geometric patterns or zig-zag designs. Outline beds with pavers or metal edging.
- Dahlias in Containers
You don’t need an in-ground bed to grow dahlias. Use pots on patios, front steps or in any sunny spot. Go for bold colors.
- Dahlias as Hedges
Neat rows of low-growing, compact dahlia varieties make vibrant, flowery hedges along foundations and property lines.
- Cutting Garden
For unlimited bouquets, devote a bed to dahlias chosen for their prolific blooms and long-lasting cut flowers. Deadhead to extend bloom time.
- Dahlias & Grasses
Let dahlias mingle with ornamental grasses for fun textural contrast. Purple fountain grass complements brightly colored blooms.
- Dahlias in Islands
Create a lush in-ground bed and dot it with dahlia varieties set off by contrasting foliage plants like coleus.
- Dahlias & Annuals
For nonstop color, surround dahlias with hardy annuals like zinnias, cosmos or petunias in complementary hues.
- Dahlias Along Fence
Maximize garden beauty by mass planting vivid dahlias along exterior fences. They’ll turn an ordinary fence into a focal point.
- Dahlias in Tree Rings
Brighten up the base of trees by filling the empty spaces around trunks with dwarf and medium dahlias.
- Dahlias in Rockery
Show off colorful dahlias to their best advantage by planting them among rocks, boulders or stone walls.
- Dahlia Borders Around Stepping Stones
Guide garden visitors along a path by bordering stepping stones with low edging varieties in white, pink or red.
- Dahlias in Sunny Backdrop
Make ordinary hedges, walls and fences pop by mass planting vivid dahlias in sunny beds in front.
- Dahlias in Sunken Bed
For drama, build a raised brick or stone planter and fill it with cascading dahlias spilling over the edges.
Design Tips for Eye-Catching Dahlia Gardens
Follow these expert tips for creating showstopping dahlia garden designs:
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Plant in groups of 3 or 5 for greater visual impact compared to single dahlias.
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Use trellises, obelisks or tall stakes to display taller dahlias without flopping.
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Contrast spiky dahlia flowers with big, round leaves like elephat ear plants.
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Weave dahlias through cottage garden favorites like phlox and sage for charm.
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Set off brightly colored dahlias with silvery foliage plants like dusty miller.
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Underplant dahlias with a living mulch like sweet alyssum for a polished look.
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Combine early, mid and late blooming dahlias for the longest season of color.
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Curate a color palette for harmony like all pink or sunset shades.
Your dahlia garden possibilities are endless. With smart planning, plant pairings and creative layouts, your dahlias will bring joy to everyone who sees them. So explore different design approaches to find your perfect match!
Companion Plants for Dahlias
In addition to combining dahlia varieties together, interplanting them with select companion plants enhances the display. Some great options include:
Annuals: zinnias, cosmos, petunias, marigolds, cleome
Perennials: coneflowers, asters, lavender, sages, coreopsis
Grasses: miscanthus, pennisetum, stipa, panicum
Vines: morning glory, hyacinth bean vine, mandevilla
Foliage: coleus, dusty miller, parsley, artemisia
Caring for Dahlias Through the Seasons
To keep your dahlias looking their best all season long, follow these tips:
Spring: Plant tubers after the last frost date once soil warms. Provide trellises or stakes for support right away.
Summer: Water during dry spells. Pinch off spent blooms to encourage more flowers. Watch for earwigs, slugs and aphids.
Fall: Cut back frost-killed foliage and carefully dig up tubers to store once they become dormant.
Winter: Store tubers in a cool, dark place. Dry them out and pack in vermiculite, peat or wood shavings. Discard any rotten tubers.
Frequently Asked Questions About Dahlia Gardens
How much space do dahlias need?
Space dahlias 12-24 inches apart depending on their mature size. Tall varieties need more room than dwarf types.
What is the best soil for dahlias?
Dahlias thrive in fertile, well-draining soil amended with compost. Sandy loam or loamy soil is ideal.
Should dahlias be deadheaded?
Yes, deadheading spent blooms encourages more flowers. Use pruners to cut just above a set of leaves.
Are dahlias good for cut flowers?
Absolutely! Many dahlia varieties make excellent cut flowers that can last up to 7 days in water. Just cut blooms early in the day.
What colors of dahlias work well together?
Some pleasing combinations are red and yellow, pink and orange, white and purple, and contrasting bicolors.
With limitless options for incorporating vibrant dahlias, think outside the box when planning your picturesque garden. Feel free to get creative with colors, patterns, heights and companions to design your ideal dahlia showcase.
CARE & STORAGE OF TUBERS
When the first set of leaves is about 8 to 12 inches high, pinch out the center bud to encourage multiple stems to grow and produce more flowers. Sometimes this process is called topping.
Bone meal can be applied 2 to 3 times between June and October to encourage blooming. If your soil is healthy, this may not be needed at all. Apply an all-purpose fertilizer at planting to get them off to a good start.
As your dahlias grow, gently encourage the stems to stay inside the cage for support. Garden twine can be tied around the outside for additional support.
If you want longer, stronger stems and bigger flowers then you’ll need to remove the two pea-sized buds flanking the central bud. For certain types, it may be beneficial to remove more buds further down the plant. See this disbudding explanation from the Snhomish County Dahlia Society.
Deadheading will keep your plants looking tidy and encourage them to continue blooming. Many gardeners report that when they regularly deadhead their dahlias, they will bloom until the first frost. Be careful not to remove new buds, which are rounded—the spent flowers have a triangular or cone shape. Make your cut slightly higher than where the stem of the flower meets a main branch. With the spent flower removed, new buds will develop at this intersection and you’ll have more flowers in a few weeks.
Planting dahlias in containers:
Low-growing or dwarf dahlias are best for growing in containers. Use a pot with drainage holes and a good quality potting mix. When starting, barely cover the tuber with soil, more can be added as the plant’s stem grows.
Get 7 tips for growing dahlias in pots in this video from Bethany @chicagogardener.
Dahlia tubers can be stored for the winter in your basement or garage. Photo by: Frances Palmer.