How to Grow Dinner Plate Dahlias and Care for Them

As a passionate gardener, few things bring me as much joy as nurturing exquisite blooms.

Among the stars of my garden are dinner plate dahlias. These flowers are not a particular variety of dahlias, however they refer to them as such due to the size of their blooms.

This unique type of dahlia produces large flowers the size of dinner plates that provide an unparalleled touch of elegance and charm.

A popular choice for cut flower gardens, dinner plate dahlias are relatively easy to grow, but do have some specific requirements for care.

Dinner plate dahlias are a type of dahlia that is characterized by its large, dinner plate-sized flowers. They are classified as either large (8-10 inches in diameter) or giant (over 10 inches in diameter) by the Dahlia Society. Most dinner plate dahlias fall into the “informal decorative” type category.

Dinner plate dahlias grow on bushy, tuberous, herbaceous perennial plants that are native to Mexico and Central America. The plants can grow up to 4-6 feet tall in the garden and several feet wide. They are perennial in warm climates, but the roots must be stored indoors in areas with cold winter climates.

In this guide, I will share with you the secrets of how to grow dinner plate dahlias and how to care for these captivating beauties in your garden.

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Growing Conditions for Dinner Plate Dahlias

Dinner plate dahlias may seem demanding, but their splendor is well worth the effort. To ensure their optimum growth, you’ll need to give them a good head start and provide them with the right conditions.

These giant flowers thrive in full sun, so choose a spot in your garden that receives at least 6-8 hours of direct sunlight each day. Well-drained soil with a slightly acidic to neutral pH (6.5 to 7.0) is essential. I like to grow mine in raised beds to give them the very best soil possible for optimal growth.

Enhance the soil’s structure and fertility by amending it with organic matter like peat moss or compost.

Dinner plate dahlia plants are heavy feeders, so plan to fertilize them regularly to fuel their growth.

Planting Dinner Plate Dahlias

Spring is the ideal time to plant your dinner plate dahlias, once the threat of frost has passed.

Plant dinner plate dahlia tubers about 3 to 4 inches deep on their sides and space them 18 to 24 inches apart.

Ensure the soil is moist but not overly wet when you plant the tubers to prevent rotting.

Do not water the dahlias until they sprout or you can cause the tuber to rot.

Staking Dinner Plate Dahlias

Dinner plate dahlias need to be staked and tied to support their large stalks and blooms.

You can use plastic or bamboo stakes.

I prefer to put my stakes in when I plant my tubers so I am sure not to damage my tubers when inserting the stakes. In addition, the stakes are ready and in place when you need them.

I like to use green coated wire to tie them to the stake. I find this method to be very easy.

Caring for Dinner Plate Dahlias

Caring for dinner plate dahlias involves nurturing and your attention. These giants require consistent watering, especially during hot and dry spells.

Water at the base of the plant to keep the leaves dry, which helps prevent powdery mildew.

Speaking of which, keep an eye out for this fungal disease, along with other potential pests like aphids and slugs. Combat them using eco-friendly solutions like insecticidal soap or Neem oil. I have been using Captain Jacks to ward off any fungus and critters in my garden.

Fertilizing Dinner Plate Dahlias

Fertilizing every 4 to 6 weeks with a balanced fertilizer will provide the necessary nutrients for robust growth and big blooms. I like to use a 10-10-10 ratio fertilizer.

Pinching Dinner Plate Dahlias

When your plants are approximately 12-16″ tall and have three to five sets of leaves. Locate the center stem between the top set of leaves and cut this off with a sharp pair of clippers.

Deadheading Dinner Plate Dahlias

Regular deadheading – the removal of spent flowers – encourages the plant to produce new blossoms and result in more abundant blooms.

Air circulation is key, so avoid crowding your dahlias and be sure to prune any overgrown branches.

Harvesting Dinner Plate Dahlias

The moment of truth arrives when those flower buds bloom into beautiful, large flowers.

The ideal time to harvest the blooms is when they are 3/4 of the way open and the petals are folding forward.

Find the central stem and follow it down to where the first set of two leaves are. If you want a longer stem, go down one more set of leaves. Don’t be afraid to cut buds off.

The more you cut, the more blooms you will get. So you can be aggressive when cutting.

The huge blooms and strong stems of dinner plate dahlias make them ideal for adding to cut flower arrangements.

However, once you cut the blooms they will not continue to open anymore like other flowers. So, don’t expect the buds to bloom.

Caring for Cut Dinner Plate Dahlias

To enjoy these magnificent blooms indoors, there are several steps you can take to maximize their beauty and longevity.

Trim the stems at a 45-degree angle and remove any foliage that would be submerged in water.

Place the freshly cut stems in a clean vase filled with lukewarm water mixed with flower food to nourish them. (or a simple splash of vinegar)

Display the vase away from direct sunlight and drafts, as dahlias are sensitive to temperature changes.

Refresh the water daily, re-cutting the stems slightly each time for optimal water absorption.

With proper care, your cut dinner plate dahlias can grace your living space with their stunning presence for up to a week.

Winter Protection for Dinner Plate Dahlias

In regions with cold winters, taking special care to protect your dahlias is essential. At the end of the growing season (before the first frost), dig up the tubers carefully, taking care not to damage them.

Shake off excess soil and let them air dry. Store the tubers in a cool (ideal temperature is 50 degrees fahrenheit) dry place over winter, ensuring they are labeled clearly for hassle-free spring planting season.

Types of Dinner Plate Dahlias in my Garden

There are many dinner plate dahlia varieties, each with their own flower form, color, and size. I have chosen a selection of four types to grow in my garden bed this year.

I purchased all of my large dahlias from Sarah’s Cottage Creations Flower Farm. This family-owned farm offers many varieties of dahlias and is a wonderful resource to give you a jump start on growing these showy plants.

In my dahlia bed you will find the elegant Café Au Lait, delightful Penhill Watermelon, striking Breakout dahlias, and the radiant La Luna.

Cafe Au Lait

Penhill Watermelon 

Breakout

La Luna

Additional Dinner Plate Dahlias

Here are a few more that I am anxious to try. You can get them @swanislanddahlias. If you order now, they are 10% off and you get a free tuber for every $100 you spend.

Clearview Jonas

Snowbound

Maki

With a bit of care, you can transform your garden into a dinner plate dahlia paradise.

To ensure success, explore different varieties, shower them with nutrients, fend off pests, and keep them snug during winter.

Let your garden bloom with the elegance and splendor of dinner plate dahlias and enjoy their breathtaking beauty year after year.

FAQs about how to grow Dinner Plate Dahlias

When should I plant dinner plate dahlias?

Dinner plate dahlias can be planted in late spring, after the danger of frost has passed. In most areas, this is after the soil has warmed to at least 60 degrees Fahrenheit.

How much sun do dinner plate dahlias need?

Dinner plate dahlias need full sun, at least 6 hours of sunlight per day. If you live in an area with hot summers, you may want to plant them in a spot that gets some afternoon shade.

What kind of soil do dinner plate dahlias need?

Dinner plate dahlias need well-drained soil. If your soil is heavy clay, you can improve the drainage by adding compost or sand. The soil should also be rich in organic matter.

How much water do dinner plate dahlias need?

Dinner plate dahlias need regular watering, especially during hot, dry weather. The soil should be kept moist, but not soggy.

How do I fertilize dinner plate dahlias?

Dinner plate dahlias should be fertilized regularly. You can use a balanced fertilizer, such as 10-10-10 or bonemeal every 4-6 weeks.

How do I deadhead dinner plate dahlias?

Deadheading is the process of removing spent blooms. This will encourage the plant to produce more blooms. To deadhead a dinner plate dahlia, simply pinch off the spent bloom just below the flower heads.

How do I protect dinner plate dahlias from pests and diseases?

Dinner plate dahlias are susceptible to a few pests and diseases, including powdery mildew, aphids, and slugs. You can control these pests and diseases with insecticidal soap, neem oil, or other organic pesticides.

How do I winterize dinner plate dahlias?

In areas with cold winters, dinner plate dahlias should be dug up and stored indoors during the winter. The tubers should be stored in a cool, dry place.

I hope you enjoyed this essential guide to growing Dinner Plate Dahlias. If you ever have a question, please feel free to email me @ [email protected].

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