Dahlias are a popular garden flower known for their wide array of bright, bold colors. They come in almost every hue imaginable – fiery reds, sunny yellows, bubblegum pinks, and more. But one color that dahlia lovers long to see is a true purple. So do purple dahlias really exist?
The short answer is yes, purple dahlias do exist. However, they are quite rare compared to dahlias of other colors. Achieving a true purple dahlia has been an ongoing quest for breeders and a coveted prize for gardeners.
In this article, we’ll take a deep dive into the world of purple dahlias. We’ll discuss:
- The challenges of breeding purple dahlias
- Notable purple dahlia varieties that have been introduced
- Tips for growing and caring for purple dahlias
- Where to buy seeds and tubers of purple dahlias
So if you’ve ever longed to add the elusive color purple to your dahlia collection, read on to learn all about these uncommon beauties!
The Challenges of Breeding Purple Dahlias
One reason true purple dahlias are so rare is because purple pigmentation is extremely difficult to achieve in dahlias.
Dahlia flowers gain their vibrant colors from plant compounds called anthocyanins. Red dahlias get their color from the anthocyanin pelargonidin. Blue and purple dahlias get their color from the anthocyanin delphinidin.
However, delphinidin is very unstable in dahlias. It tends to fade to red or turn bluish-purple rather than a true royal purple hue. This makes breeding a strong, vivid purple dahlia an ongoing challenge.
Additionally, purple dahlias tend to have weaker stems and poorer vigor compared to dahlias of other colors. Breeders must work to improve the plant’s strength and flowering power while also working to stabilize the delicate purple pigments.
The genetics and chemistry of the dahlia flower continue to make a truly purple dahlia difficult to attain. But through persistence and years of trial and error, breeders have made great strides in developing deep purple dahlias suitable for garden culture.
Notable Purple Dahlia Varieties
Despite the challenges, several promising purple dahlia varieties have been introduced over the years. Here are some of the most notable:
Hollyhill Spiderwoman
One of the closest varieties to a true purple dahlia is Hollyhill Spiderwoman. This decorative dahlia has slightly spidery petals in a rich royal purple color. The blooms can reach up to 10 inches across on sturdy branching plants.
Hollyhill Spiderwoman was introduced in the UK by dahlia hybridizer Brian Hollyhill. It has won numerous awards for its exceptional color and form. However, despite its accolades, it is still considered rare and can be hard to find for sale.
Purple Taiheijo
Another noteworthy purple is the dahlia variety Purple Taiheijo. This large cactus dahlia has elongated twisted petals in shades of light amethyst-purple. The lavender-gray color is quite unique for a dahlia.
Purple Taiheijo was bred in Japan in the mid-1900s. It became popular for its huge 8-10 inch blooms and improved purplish color. However, the petals tend to fade and bleach in sunny conditions. Keeping the blooms out of intense sun preserves their soft purple tones.
Ms Purple
Ms Purple is a striking anemone-type dahlia with spiky, thin petals. The color is a cool violet-purple that holds up well in the garden. The flowers are about 6 inches wide on top of long cutting stems.
This variety was introduced more recently by a Dutch dahlia breeder. It has quickly become popular for adding that coveted purple pop to garden beds and cut flower arrangements.
Other Notable Mentions
In addition to the varieties above, a few other purple dahlias that deserve mention include:
- Purple Gem – a small purple pompon dahlia
- ICARUS – a giant purple dahlia that can grow up to 12 inches across
- Purple Star – a purple waterlily type dahlia
- Elsie Houston – a cactus dahlia with spiky lavender-purple petals
Breeders continue to work on improving purple dahlias. Newer varieties are always being introduced that inch closer and closer to an ideal true purple color.
Growing Purple Dahlias
If you want to try growing purple dahlias yourself, here are some tips:
Site Selection
Choose a site with full sun to partial afternoon shade. Purple dahlias need plenty of sunlight to bloom well, but afternoon shade will help prevent the delicate purple pigments from fading.
Soil Preparation
Purple dahlias thrive in fertile, well-draining soil. Add ample amounts of compost and other organic matter when preparing the soil to provide nutrients. Make sure the soil drains freely – dahlias can rot in soggy soil.
Planting
Purple dahlias can be planted outdoors after all danger of frost has passed. Plant the tubers 2-4 inches deep, about 1-2 feet apart. Water the area deeply after planting.
Maintenance
Apply a balanced fertilizer every 4-6 weeks during the growing season. Water when the top few inches of soil become dry. Remove spent blooms to encourage more flowers. Stake taller varieties to provide support.
Overwintering
In zones 8 and warmer, tubers can be left in the ground over winter. In colder zones, dig up the tubers and store them dormant over winter in a cool, dry place.
Dividing
Mature dahlia clumps should be divided every 2-3 years in spring when new growth appears. This will maintain plant vigor and flowering performance.
Where to Buy Purple Dahlia Tubers
Purple dahlias can be hard to find at local garden centers. Here are some reputable online sources for buying purple dahlia tubers:
Swan Island Dahlias
This dahlia grower in Oregon offers a nice selection of purple dahlias including Hollyhill Spiderwoman, Ms Purple, and Lavender Swan.
Website: https://dahlias.com
Eden Brothers
This plant nursery sells the purple dahlia varieties Purple Taiheijo, Hollyhill Spiderwoman, and Cartouche.
Website: https://www.edenbrothers.com/store/purple_dahlias.html
Bratsch Dahlias
This specialty dahlia grower has a wide catalog of rare and unusual dahlias, including the purple variety Penhill Watermelon.
Website: https://bratschdahlias.com
You may have to search around and be patient to find available tubers of rarer purple dahlias like Hollyhill Spiderwoman. But the quest for the elusive purple dahlia is part of the fun!
Purple Dahlia Alternatives
If you have trouble finding purple dahlia tubers, all is not lost. Here are some purple perennial flowers you can grow that give a similar pop of regal color:
Purple Coneflower
Echinacea purpurea, also called purple coneflower, is a hardy perennial with flowers in shades of rosy-purple. There are also varieties with deeper purple blooms.
Purple Asters
Purple dome asters (Aster novae-angliae) provide aLate season burst of rich purple daisy-like flowers. They pair beautifully with other fall perennials.
Purple Orchids
Exotic looking purple orchids like phalaenopsis provide unique purple blooms indoors and in greenhouse growing.
Purple Tulips
Certain tulip varieties have deep purple blooms, like Queen of the Night and Purple Prince. These early spring bulbs pack a punch of purple to the garden.
Purple Violas
Cheerful purple violas (viola sororia) bloom abundantly in cool weather and combine nicely with other early season annuals and perennials.
While not exact substitutes for the stunning purple dahlia, these plants can provide your landscape with gorgeous purple hues through much of the year.
Conclusion
So do purple dahlias exist? The answer is yes! Stunning purple varieties like Hollyhill Spiderwoman and Purple Taiheijo demonstrate that the quest for a true purple dahlia has largely been achieved.
However, purple dahlias are still quite rare compared to their red, pink, and yellow cousins. The genetics of the dahlia continue to make breeding a strong, garden-worthy purple dahlia an ongoing challenge and thrill for hybridizers and collectors.
If you have a purple obsession, search for these uncommon purple dahlia tubers from specialty growers. Then give them a prime spot in your sunny garden where you can show off their royal color. And if you can’t find purple dahlias, give some of the other purple perennials a try to infuse your beds and borders with regal purple hues.