Dinner plate dahlias are not plants that one would call shrinking violets. They are impressive in a garden and make wonderful cut flowers for arrangements.
These majestic plants command attention in a garden bed and also need plenty of room to grow and flower.
Keep reading for tips for how to grow these magnificent dahlias in your garden.
Penhill Watermelon dahlia
A master of a plant – dinner plate dahlias
Brush up on your knowledge of these fun facts about these heat-loving perennials.
Dinner plate dahlias don’t belong to a specific category of dahlias. The term is used for any variety of dahlia that produces flowers at least 8 inches across.
Café au lait dahlia
- plant type – tuber, perennial
- botanical name – dahlias
- family – asteraceae
- common name – dinner plate dahlia
I love dahlias and zinnias, and blanket flowers, and coneflowers….and on and on. Basically anything that looks even somewhat like a daisy, my birth flower, is a favorite of mine.
Dahlias are not an easy plant for me to over-winter in my zone 7 b garden. There are some winters when it MIGHT last through the cold months and grow again, but I never take the chance.
These are warm temperature plants, and are cold hardy only in zones 8 and above.
I dig up my dahlias in the fall, wash off the dirt and dry them out. Then I store them in peat moss and replant again in the spring.
Otto’s Thrill dahlia
How to care for dinner plate dahlias
Care for these large dahlias they way you would any type of dahlia. Here are some dinner plate dahlia care tips.
Choosing dinner plate dahlias
Some gardeners refer to dinner plate dahlia bulbs, but they are actually grown from tubers. If possible, try to select those that come from plants that you know will produce very large flowers.
These beauties aren’t called “dinner plate” without good reason. You will want a show of very large flowers.
Thomas Edison dahlia
When to plant these large dahlias
Plant the tubers in the spring when the ground is consistently above 60 degrees and danger of frost has passed.
This could be as late as May or June, depending on where you live.
Choose a spot where the mature dinner plate dahlias won’t overshadow other plants. The back of a sunny border is a good spot.
When to plant dinner plate dahlias
The hole should be twice the length of the tuber. Add some organic matter or compost to the hole. The plants will also benefit from regular fertilizing with an all purpose flower fertilizer. (affiliate link)
Dahlias are not particular about soil type. They will grow in soil with a PH of acid, neutral or alkaline.
Plant dinner plate dahlia tubers 36 inches apart. They need room to spread! Each tuber can produce up to a dozen flowers on stems four feet tall.
Fill the hole just up to the base of the stem with the stem sticking out of the ground. As the plant grows, gradually add more soil up the stem.
This will make the plant much stronger as it grows and gets heavier. (This is a good way to plant tomato plants, too.)
Watering and sunlight needs for dinner plate dahlias
Begin watering when the plants are actively growing, being sure to water regularly and deeply to encourage deep roots.
Make sure the soil drains well. Soggy soil will stunt the growth of dinner plate dahlias.
Be sure to plant in a sunny location. All dahlias like full sun.
Dinner plate dahlia flowers
The variety of flower types with these super-blooms is amazing. Some are decorative with perfectly cupped petals.
Some have two colors of petals and others just one. A few are twisted, quilled or shaggy.
Choose from single or double petal varieties. As long as they will produce at least 8 inch blooms, they are classified as a dinner plate dahlia.
Belle of Barmera dahlia
Common questions about these super blooms
Readers love these big blooms are much as I do. Here are some common questions that I receive.
- How tall do dinner plate dahlias grow? The stems may reach four feet or even taller!
- When do dinner plate dahlias bloom? Most dinnerplate dahlia will start to bloom about 8 weeks after planting and will bloom until fall if you remove spent flowers.
- Why are my dinner plate dahlias small? This can be the result of dahlia mosaic virus. Unhealthy tubers can be stunted, as well as their flowers.
- Are dinner plate dahlias perennials? While these dahlias are classified as a perennial, they are not cold hardy below zone 8.
Share this post of growing tips for dinnerplate dahlias on TwitterDinner plate dahlias are not shrinking violets in the garden. These super blooms will grow to 8 inches wide on 4-5 foot stems. Find out how to grow them on The Gardening Cook. #dinnerplatedahlias #superblooms 🌺🌺🌺 Click To Tweet
Staking dinner plate dahlias
One way that dinner plate dahlias require some extra care over normal dahlias is that they always require staking.
Because the flowers of Dahlias are so heavy, they will need some sort of support. Keep an eye on your plants as they grow and if they start to lean or flop over, use something to hold them erect.
Deadheading these super blooms
As much as we would like to skip the task of deadheading, if you remove the spent blooms as they die off, you will enjoy dinnerplate dahlias from midsummer through until fall.
Cold hardiness for dinner plate dahlias
These large dahlias are only cold hardy in zones 8-11. In other zones, the first frost will kill your leaves and flowers.
If you want to grow them again next year, dig up the tubers, wash off the dirt and let them dry out.
Store them in peat moss in a cardboard box in a cold location (affiliate link.) The peat moss might need a bit of misting through the winter.
Replant the dahlias in the spring when the ground is 60 degrees, danger of frost has passed, and you will have another season to enjoy them.
Some of the links below are affiliate links. I earn a small commission, at no extra cost to you if you purchase through an affiliate link.
Dinner plate dahlia varieties
Dinner plate dahlias come in a wide range of color and shape. If you are looking to grow these super blooms in your garden, you have a lot of choices.
Some of my favorite are:
- Mystery Day – magnificent, eye-catching purple red flowers edged in white. The double flowers are not too top heavy.
- Penhill Watermelon – stalks grow up to five feet tall and flowers can reach 10 inches wide.
- Babylon Bronze – this has a double bloom that is a stunning pale orange color.
- Café au Lait – creamy peach flowers that have a very subtle look.
- Belle of Barmera – double two-toned blooms, in hues of coral, and raspberry, with peach centers.
For other dinner plate dahlias for sale, try Etsy and Amazon. Both sites have them in stock right now.
Pin this post for how to grow dinner plate dahlias
Would you like a reminder of this post for growing this large dahlia? Just pin this image to one of your gardening boards on Pinterest so that you can easily find it later.
One of the Fan’s of The Gardening Cook on Facebook, Gary L, shared these photos of the dinner plate dahlias from his garden.
This photo shows the staking needed for the top heavy plants so they day don’t flop over. They are the tall show stoppers for sure!
Admin note: this post for dinnerplate dahlias first appeared on the blog in September of 2013. I have updated the post to add all new photos, a printable shopping list, and a video for you to enjoy.
Shopping List for Dinner Plate Dahlias
Dinner plate dahlias have blooms that are 8 inches wide on stems that can be four feet long. They are real show-stoppers in the garden.
Print out the shopping list and take it with you the next time you go shopping for dahlias.
- Heavy card stock or printer paper
- Computer printer
- Load your printer with heavy card stock or printer paper.
- Choose portrait layout and if possible "fit to page" in your settings.
- Take the shopping list with you the next time you go plant shopping.
Using this print function on this card will print a calendar that fills about 3/4 of an 8 x 11 sheet of paper.
To fill the entire page, choose "fit to page" on your printer if you have this setting, or use the link in the post above and print using the browser print feature
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Thursday 24th of May 2018
Some of my dinner plate dahlias have not started growing. Most yard several inches tall. What should I do? Donna
Thursday 24th of May 2018
Hi Donna. It is hard to say exactly. There are a few reasons why dahlias won't bloom. They need at least 6 hours of sun a day. They also need even moisture, so if you are not watering them enough they won't bloom. Also over fertilizing can be a problem for them since they will grow lots of leaves but no flowers. Carol
Sunday 8th of January 2017
Would you be interested in trading tubers? You can look at the ones I have on my website. I will not be able to trade every dahlia because I sell bouquets and need a specific amount of each kind.
Wednesday 16th of April 2014
Thanks for your lovely post. I live in a Colorado at about 7000 ft. Can I grow these in large containers on my very sunny deck?
Wednesday 16th of April 2014
They would grow but having them in containers would mean watering much more often. They would not overwinter though and would need to be dug up.
Tuesday 1st of April 2014
Where can I buy these, please? Beautiful.
Friday 25th of March 2022
@Elaine, I found some very nice collections at K Van Bourgedien, Gilbert H Wild and LongfieldGardens. Be sure Not to water the plants until there is developed root structure and about 8-12 inches of foliage. They come from the arid high desert of Mexico and will rot if given too much water before they can handle it. Growing the bulbs in perlite, peat and bark is highly recommended. Adding in mycorrhiza will help to encourage the root growth. Good luck. 🍀🌺🌸
Tuesday 1st of April 2014
Most online garden centers have them for sale. Just Google "dinner plate dahlias for sale."