Dahlia Hybridization: Should I Keep This Bloom?

Are you growing dahlias from seed? Did you know they will make small clumps by the end of the summer, which you can dig up to save and replant next year?! It’s such a fun process to grow dahlias from seed and try to find amazing new varieties!

Although we believe every dahlia is beautiful, not every dahlia seedling is a “keeper.” Today we’re beginning a helpful series on how we decide which ones make the cut here at Triple Wren Farms! We consider these four things:

Bloom
Vigor
Plant Habit
Tuber

Let’s start with blooms. Blooms are the most obvious characteristic to consider since that is why we grow dahlias in the first place! Those luscious blooms! There are four main considerations with assessing your beautiful new dahlia bloom: color, form, bloom position, and bloom attachment. Let’s talk about each one of those.

Blooms

Color

When looking at a bloom, first evaluate the color. At TWF, we grow every color of dahlia, but we specialize in growing dahlias for cut flowers in a modern palette. For us to put time into cultivating a new hybrid, it has to be in a desirable color. For example, there are not nearly enough light blend dahlias in peach, coral, cream, lavender, and “mocha” palettes, and those are the ones we prioritize.

Form

In addition to color, we also evaluate the form. For our TWF dahlia breeding program, we only keep collarette, anemone, waterlily, formal decorative, informal decorative, ball form, really special laciniated forms, and really special novelty forms. (If you need a refresher on dahlia forms, you can check out our post on it here.) Some of this decision is personal preference, but most of it is which dahlias tend to be the most popular and sell the best. We keep only blooms that show the proper characteristics for each form and are free from defects like open centers or off-color petals, etc.

Bloom Position

If you’re pleased with both the color and the form, you now need to evaluate the position of the bloom. This is not where the bloom is on the stem itself (it’s at the top!), but the angle that the bloom presents itself on the stem. The American Dahlia Society prefers a bloom position at 45 degrees, but will allow a top facing bloom position for some forms. If you’re just growing for pleasure, you’ll want the bloom to angle upwards, not downward or at 90 degrees, for best success in bouquets.

Bloom Attachment

Finally, you also need to evaluate the attachment. This is not how attached you are to a particular new bloom in your garden! Attachment refers to how well the bloom stays put on the stem. Does the bloom easily pop off the stem? Does it wiggle a lot? If it does, it’s not necessarily a deal breaker since there are some artistic ways to use dahlias without the stem, but that definitely makes it less desirable for florists. We choose to keep only dahlias with super strong attachments for our hybridization program.

Take Notes

It is very important to take notes and pictures throughout the season about any dahlia blooms you’re interested in keeping! Sometimes the dahlia blooms can change based on temperatures and length of days. There are so many factors that go into hybridizing a new dahlia variety and it’s imperative to take notes to keep track of your new dahlia over multiple growing seasons. It’s a lot of note-taking and observing at the beginning, but it’ll be so worth it when you have your own dahlia hybrid some day!

Want to learn more about growing dahlias?

The Garden is a positive online membership community offered by Triple Wren Farms. Membership includes:

First access to TWF tuber and seed sales
A wealth of flower garden How-To topics
Frequent seasonal Live Trainings and Q&A’s
Our “Anyone Can Grow Dahlias” e-course
Personalized gardening advice
Encouraging gardening community and more…

Visit our website to find details and join The Garden!