Our ten-step plan for how to grow dahlias

Because I write fiction, I’m sometimes inspired to add a few literary devices when I blog. For example, I included the use of personification, alliteration, and metaphors in my last post when I introduced you to the “king of the garden”, or the dahlia. Today, however—since I also write nonfiction—I’ve chosen to set most of my narrative techniques aside and speak to you more matter-of-factly. Now, that my current choice of writing style is out of the way, let’s move onto the subject at hand.

Whether you are a cut flower farmer or a home gardener who’s eager to grow a new bloom, cultivating a crop of dahlias is a relatively straightforward process as long as you carefully craft a plan and implement it. This post’s purpose is to help you get started on the right foot by offering you our ten-step plan as a go-by.

You might wonder, though, why, I as a flower farmer would share with you what I did to grow my crop of dahlias. Well, that’s simple. I’ve said it before, “The more flowers we plant? The better our general outlook is on life, and the better off our pollinators will be.”

I may want to make a profit from growing and selling flowers but that doesn’t mean I don’t want to help you raise a few more blooms.

OK, so let’s go.

After doing a lot of research this past February and sharing it with my husband, we both sat down in our kitchen to cautiously create our plan.

This would be a new crop for us so we did not want to make a lot of unnecessary mistakes during the planting and harvesting stages due to our not adequately knowing enough about growing dahlias before we even started.

Put plainly, this is the ten-step plan we devised:

  1. Research
  2. Order tubers and other supplies
  3. Prepare soil
  4. Plant and stake (if not done already)
  5. Pinch
  6. Water
  7. Fertilize
  8. Deadhead
  9. Harvest blooms (sell, share, and enjoy them)
  10. Dig up tubers and store for the 2023 season

Let’s now look at the first step, research.

I’m going to list a few basic but important facts that I learned while doing my investigation of dahlias. I will include other details when I address each additional step in my future posts.

Now for the basic facts…

As I described in my last post, dahlias are native to Mexico and parts of Central America. As a result, these plants love warm temperatures including soil temperatures that do not fall below 60°F.

Dahlias flourish in enriched soil that drains well; they do not enjoy residing in swamps devoid of nutrients.

Dahlia plants grow from tubers underneath the surface of the soil. Other common plants that grow from tubers are potatoes and carrots. Like potatoes and carrots, dahlia tubers can be eaten and many of those who eat them say they are delicious.

Dahlia tubers should be planted in 8-inch holes approximately 8 to 12 inches apart. After planting the tubers, it normally takes about 120 days for those dahlias to produce flowers.

There are more than 40 different species of dahlias ranging in plant size, color, form, and bloom size.

Regarding the official classification of dahlias, there are more than 57,000 registered cultivars. They are often officially classified by 3 characteristics: form (type of flower), color, and flower size. As a result of the many combinations that can be produced from these 3 characteristics, it is not surprising that there are thousands upon thousands of registered cultivars.

Several dahlia societies exist around the globe. One such society is the American Dahlia Society or the ADL. This society, as can be expected, categorizes dahlias according to form, color, and flower size. The ADL lists 15 forms, ranging from anemone to water lily, 15 colors, ranging from red to purple, and 7 flowers sizes, ranging from 2 to 10 inches.

Let’s examine briefly one of these official characteristics, flower size. The American Dahlia Society’s seven sizes are as follows:

Giant: AA (over 10 inches)

Large: A (8 – 10 inches)

Medium: B (6 – 8 inches)

Small: BB (4 – 6 inches)

Miniature: M (up to 4 inches)

Micro: MC (up to 2 inches)

In many gardening circles, however, you will commonly hear dahlia blooms described by using two terms that do not place them in an official class. These terms are dinner plate and semi-dinner plate. Dinner plate refers to blooms of eight or more inches in diameter, or about the size of an average dinner plate you might eat from, and semi-dinner plate refers to blooms that are of about half the diameter of that same dinner plate.

After considering the basic facts and researching various cultivars, I created a list of 23 different cultivars, differing in form, color, flower size, and plant size to grow this season. Here are five from my list with their classifications from the American Dahlia Society as well as photos of a few I planted: ‘Crazy Love’, “House of Orange’, ‘Café au Lait’, ‘Sylvia’, and ‘Babylon Red’.

As per the ADL, formal decorative means that the “petals” are “generally flat, broad, and smooth in a regular arrangement that gradually recurve toward the stem” and informal decorative means the “petals” are “generally twisted, curled or wavy, and of uniform size to irregular arrangement” and “may be involute or revolute”. According to Oxford Languages the world involute means “curled spirally” and revolute means “curved or curled back”.

Take a moment to examine the photos of all five different cultivars and try to identify why the flowers in the photos are classified as they are.

Crazy Love

  • Class: 3101
  • Form: Informal Decorative
  • Color: White
  • Flower Size: BB (Small, 4 – 6 inches)

House of Orange

  • Class: 2003
  • Form: Formal Decorative
  • Color: Orange
  • Flower Size: B (Medium, 6 – 8 inches)

Café au Lait

  • Class: 2104
  • Form: Informal Decorative
  • Color: Pink
  • Flower Size: B (Medium, 6 – 8 inches)

Sylvia (Sylvia Craig Hunter)

  • Class: 2003
  • Form: Formal Decorative
  • Color: Orange
  • Flower Size: B (Medium, 6 – 8 inches)

Babylon Red

  • Class: 2006
  • Form: Formal Decorative
  • Color: Red
  • Flower Size: B (Medium, 6 – 8 inches)

Excellent! Now, that you know a little more about dahlias, I bet you already recognized that if you were ordering the tubers for the plants above either online or from a gardening store, due to their blooms’ sizes, ‘Crazy Love’, ‘House of Orange’, ‘Café au Lait’, and ‘Sylvia’ might likely be described as semi-dinner plate while Babylon Red would be likely referred to as dinner plate.

Good. You have successfully completed step one of our plan for growing dahlias. Regarding the next three steps, #2-4, however, I’ll explain what Jim, our kids, and I did to implement each one of these steps in my next post. Rather than overwhelm some of you who may be new to the world of dahlias, I would instead prefer to break the subject down and serve it to you bit by bit—or since we are talking about dahlias—dinner plate by dinner plate.

Until my next post, best regards! SB