Dahlia Flowers: How to Plant This Versatile Herbaceous Bloom?

There is no better sight than watching dahlias bloom and grow in your lawns and gardens. A splendid show of colours ranging from light pink, white and lavender to bold red and purple, the contrast looks breathtaking. 

I have grown dahlias both as a perennial and an annual, depending on the climate of the place I have lived in, and the care of dahlias is something that I never have to worry about because the result is worth all the effort. 

It’s unlikely that any experienced gardener has not grown dahlia flowers ever. But worry not if you have not, and come along and explore the easy planting and care guide of the dahlias with me. 

What is the Dahlia Flower? A Versatile Flowering Genus 

Similar to the dianthus flower, dahlia is a flowering genus that has over 42 species and thousands of varieties of plants under it. This herbaceous plant features round, symmetrical flowers with layered petals that give a pompon-like look to the bloom. 

Along with the peperomia plant, dahlia flowers are also native to the region of Central America and Mexico, and are mainly grown in the United  States. Also known as “valley flowers”, the word dahlias is named to honour the Swedish botanist Anders Dahl. 

These perennial plants usually reach up to a height of 6 feet and grow in almost every colour, ranging from pink, red and yellow to purple, with thin stems and bright green leaves. 

Before getting into the dahlia flower planting guide, have a look at its scientific classification. 

Botanical name	Dahlia pinnata
Kingdom	Plantae
Division	Magnoliophyta
Class	Magnoliopsida
Order	Asterales
Family	Asteraceae Bercht. & J. Presl
Genus	Dahlia Cav.

What are the Different Varieties of the Dahlia Genus? 

The dahlia flowers have approximately 6 thousand cultivars divided into more than 30 species, and like the types of lettuce, they are classified into different groups based on their appearance. 

Take a look at the most famous dahlia varieties: 

Name	Features
	Café au Lait Royal  Botanical name: Café au Lait Royal  Colour: Pink  Flower size: 8-10 inches  Height: 4 feet  Flower Type: Decorative dinner plate
	Miss Delilah  Botanical name: Dahlia ‘Miss Delilah’ Colour: Light pink  Flower size: 6 inches  Height: Up to 4 feet  Flower Type: Water lily
	Maya Dahlia  Botanical name: Dahlia ‘ Maya’ Colour: Soft pink and yellow  Flower size:  6 inches  Height: 3 feet  Flower Type: Formal decorative
	Penhill Watermelon  Botanical name: Dahlia ‘Penhill Watermelon’  Colour: Pink  Flower size: 12 inches  Height: 5 feet  Flower Type: Decorative Dinnerplate
	Sylvia Dahlia Botanical name: Dahlia ‘Sylvia’  Colour: Orange  Flower size: 4 inches  Height: 4 feet  Flower Type: Ball type

What are the Ideal Growing Conditions for Planting Dahlias? 

The best time for planting dahlias is early spring, when the soil is warm and will not shock the roots. Another thing to note is that, like the bleeding heart plant, dahlia flowers also consistently need moisture and are not drought-hardy. 

If you are planning to plant the dahlia flower, here are the ideal growing requirements for the same: 

Soil Type	Sandy loam, slightly acidic  pH- 6.0- 7.0
Hardiness	USDA zones 8-11
Sunlight Requirements	8 hours of direct sunlight
Water	3 times per week ( keep the soil moist)
Fertiliser	Low nitrogen fertiliser ( 5-10-10)

How to Grow Dahlia Flowers? 7 Step Planting Guide 

Planting dahlias using bulbs is the most reliable way, and I have been following the 7-step planting guide that has done wonders for me over the years: 

If you are confused as to how to have the best yield of dahlias, here is my tried and tested guide for the same: 

1. Loosen up the soil in the desired area. Make sure the soil is well-draining and receives at least 6 hours of direct sunlight. 

2. Add a layer of compost to refine the soil quality for better growth. 

3. Dig a hole and place the dahlia tubers in it. You do not need to remove the individual tubers; the cluster will grow a much healthier plant.

4. Cover it with a layer of soil and avoid watering immediately, as it can lead to root rot. 

5. Water the dahlia plant when the first sprout appears.  

6. Add a layer of mulch, not too close to the roots, to retain moisture and suppress weeds. 

7. Feed the dahlia plant with a low-nitrogen fertiliser 4 weeks after planting and repeat this every 3 weeks of the growing season. 

Note

Dahlias are grown as annuals in colder temperatures, precisely the USDA zones below 7. Hence, always be aware of the plant and climate compatibility for better maintenance. 

Also read: How to Grow Grapes? Cultivation, Care And Fun Facts About the Grape Vines

How to Harvest the Dahlia Flowers for Cut Blooms? 

Harvest the dahlia flowers when the flowers are ⅔ open. I harvest them early in the morning when they are perfectly hydrated. 

If you are planting dahlias for cut flowers, here is a harvesting and storing  guide: 

1. Use a sharp garden shear and cut the stem down to 12 inches above a set of leaves. 

2. Do not use your hands to harvest dahlias; using your hands can cause a tear in the stem, which affects the future blooms and can eventually hinder the growth of the plant. 

3. After harvesting, put the blooms in warm water for 1 hour and transfer to a vase with normal tap water. Adding flower food will enhance the life of the blooms. 

How to Take Care of Dahlias? 

The answer to ‘how to care for dahlia?’ is pretty simple: just make sure all the growth requirements are met, along with a few additional tips that I highly recommend, and you are good to go. 

Watering Dahlias 

1. The dahlia flowers are not drought-hardy, even though they are tubers and store water for dry spells, but the soil needs to be consistently moist to have healthy growth. 

2. Look out for waterlogging to prevent root rot. 

Deadheading the Dahlia flowers 

1. Deadheading the dahlias is best done during late fall when the plant has reached a height of 8 inches and the maximum blooms have dried and died. 

2. Snip off the stem of the damaged bloom above a set of leaves using a pruning shear. 

3. Pruning not only encourages growth but also makes the plant look more structured and tidy. 

Fertilising Dahlias 

1. Dahlias are heavy feeders just like the broccoli plant, hence feed the plant with low-nitrogen and high-phosphorus fertiliser 1 month after planting. 

2. After that, consistently fertilise the plant every 3-4 weeks. 

3. Using high-nitrogen fertiliser encourages the growth of foliage over flowers, hence avoiding it completely.  

Staking Dahlias 

1. Staking is essential for the taller varieties of the dahlias. As they grow, large blooms and have weak stems; staking helps in an upright, vertical growth and prevents them from falling. 

2. Place a wooden or metal stake 10 inches deep and about 4 inches away from the plant. 

3. Tie the plant to the stake using a string as soon as the plant grows up to 1 foot tall. 

Pests and Diseases 

Much like the kalanchoe flower, the dahlias are also susceptible to various pests and require regular maintenance and care. 

Take a look at this table to have a better understanding of the same: 

Pests	Problem	Solution
Aphids	Distorted leaves and mould growth.	Spray an insecticidal soap or use Neem oil.
Earwigs	Tear the leaves and the petals, leaving small holes in them.	Use Neem oil spray. Another option is to use a bamboo stake trap or any commercial ones available online.
Thrips	Leads to stunted growth and curled leaves.	The best way to treat thrips is to use an insecticidal soap.
Slugs and Snails	Leaves a slime-like substance behind with holes in leaves and flowers.	Remove them by handpicking at night. To control their spread, remove the debris and water consistently.

Dahlia Flowers Benefits as per Scientific Research

The dahlia flower has been a rich source of antioxidants, which have been used as a potential medicine against inflammation and diabetes. Being a curious and aware gardener, I wanted to explore medical studies on dahlias. 

Here are the 2 research papers on the benefits of dahlia flowers that I came across.  

Research summary box 1  Study year: 2023 Aim: To assess the antidiabetic properties of the dahlia flower extracts Sample type: Dahlia flower extracts, Mice(fed with high-fat diet)  Key findings:  The dahlia flower extract has a compound called butein, which was effective in managing the insulin levels. It was observed that, along with butein, it also contains certain flavonoids that contributed to this antidiabetic potential. This trial was also done on humans, and it was concluded that the same is effective for humans as well. At last, the study concluded that the dahlia flower extracts can improve insulin functions.  Source: National Centre of Biotechnology Information

Research summary box 2  Study year: 2022  Aim: To assess the anthocyanic profile and antioxidant activity of the Dahlia flower extracts  Sample type: Dahlia flower extracts  Key findings:  Dahlia flower extracts were purified using the Amberlite-XAD7- HP resin. These extracts were assessed for their antioxidant potential using the DPPH assays, and the results show significant antioxidant activity (2.6/12 g-ml). Additionally, the anthocyanic profile was assessed using the HPLC and the UPLC. The result of the UPLC profile presented 4 major components of anthocyanin, which verifies the dahlia flower extract as a potential source of anthocyanin. Source: National Centre of Biotechnology Information

Fun Facts About the Dahlia Flowers 

Have you ever wondered why flowers are extremely significant to some cultures? Is it just the beautiful colours and shapes? Well, I think the most intriguing things about blooms are the hidden fun facts that almost stay hidden for a long time. 

Well, not for dahlias, as I have curated these fun facts about these perennial blooms that you must know! 

1. Not just native, but Dahlias are also the national flower of Mexico, symbolising the rich history and diversity of the country. 

2. The ASPCA states that Dahlia is toxic for cats, dogs and horses. Ingestion can cause gastrointestinal issues. 

3. With a wide range of colour palette, you will be surprised that dahlias do not grow a blue variety. 

4. Not only the petals but the tubers of all varieties of the dahlias are edible. 

5. Historically, the Aztecs, a civilisation in Mexico during 1300, used the dahlia stem as water pipes. 

Concluding Remarks 

What better way to welcome the spring than planting dahlias? My favourite time of the year is when I get myself dahlia tubers and begin prepping for planting. This perennial plant has graced my garden with its vibrant colour palette for so many years that I have honestly lost count. 

If reading this made you want to grow dahlias, then my only advice would be to take multiple tubers of different varieties and plant them together. You will love the landscape when it grows up. 

Happy Planting! 

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