The dinner plate dahlia is an informal category of the largest varieties of dahlia flowers. These large 8″-12″ wide flowers typically have layers of petals and truly are the size of a dinner plate. Some of the most popular dinner plate dahlia varieties are Café Au Lait, Kelvin Floodlight, and Labyrinth.
Dinner plate dahlia basics
Dinner plate dahlias are specific dahlia varieties with big blooms that are wider than 8″ across when in full bloom. These large flowers tend to unfurl their petals in a flattened shape that resembles a dinner plate. Some can reach as large as 10″-12″ wide! The plants are easy to grow but require staking. Dinner plate dahlias tend to start blooming in July and continue to flower until the first hard frost of Autumn (often in October).
While Dinner Plate Dahlias are not a specific type of dahlia as defined by the Dahlia Society, all Dinner Plate Dahlia varieties fit into the Dahlia Society’s Size Classification Guide as sizes Large (8″-10″ wide) or Giant (over 10″ wide). Most Dinner Plate Dahlias fit into the “Informal Decorative” type category of dahlias.
Dinner plate dahlias grow on bushy, tuberous, herbaceous perennial plants native to Mexico and Central America. The plants can be 4′-5′ tall in the garden and several feet wide, making them seem almost like small shrubs. The plants are perennial in warm regions, but the roots must be stored indoors in areas with cold winter climates.
“Giant, 10+ in (25+ cm), Also Known As AA: These are often referred to as dinner plate dahlias. The massive blooms in this class require a little extra protection from weather due to their tremendous size and delicate nature. Well suited for large-scale arrangements, these beauties are real showstoppers.”
Dahlia Sizes, Floret Farm’s Discovering Dahlias: A Guide to Growing and Arranging Magnificent Blooms, by Erin Benzakein
Buying dinner plate dahlia plants
Dahlias are sold as either tubers (bulb-like roots) or as potted plants. If you’re buying the roots in person, look for healthy-looking, plump tubers that are free of bumps, bruises, or other damage. If buying potted plants, make sure the plant has sprouted well, has a good root system, and is not rootbound.
Dinner plate dahlia varieties
There are dozens of gorgeous dinnerplate varieties to choose from.
1. Café Au Lait
Café Au Lait is the most popular variety of dinner plate dahlia. The flowers are a beautiful creamy white color with a light pink hue. The flat-shaped blooms can be 8″-10″ wide and have ruffled edges.
2. Kelvin Floodlight
Kelvin Floodlight is another popular variety. The flowers are bright yellow with a hint of orange. They are 10″-12″ wide and have ruffled petals.
3. Labyrinth
Labyrinth is a beautiful Dinner Plate Dahlia with bicolor pink and orange flowers. They are 8″-10″ wide and have ruffled petals.
4. Pomona
Pomona is a gorgeous Dinner Plate Dahlia with pink flowers. They are 8″-10″ wide and have ruffled petals.
5. Strawberry Fair
Strawberry Fair is a beautiful dinnerplate with deep red flowers. They are 8″-10″ wide and have ruffled petals.
6. Spartacus
Spartacus is a deep crimson red dinner plate dahlia. The flowers are 8″-10″ wide and have ruffled petals.
7. Sunburst
Sunburst is a beautiful dinner plate dahlia with yellow flowers. They are 10″-12″ wide and have ruffled petals.
8. Tahiti
Tahiti is a beautiful dinner plate dahlia with white flowers. They are 8″-10″ wide and have ruffled petals.
9. Lavender Perfection
Lavender Perfection is a beautiful dinner plate dahlia with lavender flowers (see more purple dahlias). They are 10″-12″ wide and have ruffled petals.
10. Emory Paul
Emory Paul is a beautiful dinnerplate dahlia with orange flowers. They are 10″-12″ wide and have ruffled petals.
When to plant dahlias outdoors
Wait to plant dahlias outdoors in the spring until all danger of frost has passed. The soil should be warm – at least 60°F. These are not cold-weather plants!
For early flowers, plant the tubers in a pot indoors for a month or two to get a head start. You can generally plant them indoors about a month prior to the average last frost date in your local area. Then transplant the sprouted plant outdoors once the soil warms.
Dahlias are very sensitive to cold. They tend to thrive in warm weather with lots of sunlight. Dahlia tubers are generally planted in the garden around the same time as tomato plants (usually in April or May in most temperate climates).
Where to plant dahlias in the garden
Dahlias need full sun – at least 6 hours of sunlight per day. They also need well-drained soil. If your soil is heavy, clay-like, or tends to hold water, amend it with compost or other organic matter prior to planting.
You can plant dahlias in the ground or in containers. If you live in an area with a short growing season, planting in large containers (at least 8″ deep and 12″ wide at minimum) may be the best option as it will allow you to bring the plants indoors if necessary due to an early fall frost. That said, these plants are large and often grow more flowers when planted in the ground or in a raised garden bed.
How to plant dinner plate dahlia tubers
Dinner plate dahlia tubers are easy to plant. You can soak the tubers in clean water for a few hours prior to planting, but this is not strictly necessary.
Dig a hole about 4”-6″ deep. Place the dahlia tuber into the hole with the “eye” facing upwards towards the sky. The plant stem will grow up out of the eye (hence the saying “eye to the sky”).
Mark the planting spot with a stake and label the variety. Plant dahlias about 2 feet apart. Some farms grow these plants as close as 1 foot apart if space is limited. Water deeply after planting.
Watering dahlia plants
Big dahlia plants need ample water to thrive. They should be watered deeply and regularly throughout the growing season, especially during dry spells. Mulching the soil with organic compost will also help the soil retain moisture.
Use drip irrigation or soaker hoses to water at the base of the plant if possible. If overhead watering, it is best to water early in the day so that the leaves have time to dry off before evening. This will help minimize the risk of fungal diseases.
Staking dinner plate dahlias
Dinner plate dahlia plants need to be staked. The stems are generally not strong enough to support the weight of the flowers. Staking dahlia plants is very similar to staking tomato plants. The best time to stake the plants is during planting or when the plant is about 2′ tall.
You can use any type of garden stake. Bamboo stakes are a popular option as they are inexpensive and easy to find. Just make sure that whatever you use is tall enough to support the plant without toppings over (at least 4 feet tall).
Drive the stake into the ground next to the plant. Use twine or soft garden ties to secure the plant stem to the stake. Be careful not to damage the stem as you tie it.
As the plant grows, continue to tie it loosely to the stake at 12″ intervals, making sure that there is some give. This will help prevent the stem from breaking in high winds.
Pinching dahlia plants as they grow
Pinching the stems of young plants can encourage plants to grow strong stems. Wait until plants are about 10″-12″ tall, and then snip off the top few inches with sharp pruners. The plant will grow more branches below where it has been cut. These branches tend to be thinner and stronger (not hollow) than if plants weren’t pinched.
Fertilizing dahlias
Dahlias (especially the bigger plants, like dinnerplates) are heavy feeders and should be fertilized throughout the season. A general-purpose fertilizer can be used as long as it’s not overly high in nitrogen. Fertilize every 2-3 weeks or according to package directions starting when plants are about 12″ tall. If you are using organic compost, you may not need to fertilize as often.
Dahlia blooming season
Dinner Plate Dahlias typically start blooming in blooms from mid-July through the end of the growing season when frost arrives. The more flowers are cut off the plant, the more the plant will grow as it attempts to set seed. For the largest flowers, remove the two side buds off each stem before they get too big, leaving only the one large middle bud.
Protecting dahlia blooms
Dinner plate dahlia blooms often must be protected from pests like Japanese beetles. The best way to protect the blooms is to use a physical barrier like netting or silk bags over the flower heads. You can also pick the beetles or other large pests like slugs off the plant whenever observed.
You can also use insecticidal soap or neem oil if necessary. Be sure to follow the directions on the label and only treat the plants in the evening so that bees are not harmed.
Cutting dinner plate dahlia blooms for bouquets
Dinner Plate Dahlia blooms make beautiful large-scale bouquets. The best time to cut the blooms is in the morning after the dew has dried but before the heat of the day sets in. Try to cut each bloom as soon as the flowers open for the longest vase life.
Cut the stem at an angle with sharp pruners. Place the cut stems in water immediately. Dahlias have a fresh vase life of 3-7 days, depending on conditions. Change the water daily and re-cut the bottom of the stems each day for the longest life.
