Shiplap and Shells

Home and Garden in the PNW

  • My Blog
    • Home Decor
      • Spring
      • Summer
      • Fall
      • Winter
        • Winter Holiday & Christmas Inspiration
      • Our 100-Year-Old Beach House
      • Entertaining
    • Garden
      • Growing a Cut Flower Garden Series
      • Tips and Tutorials
      • Spring
      • Summer
      • Fall
      • Winter
    • Saltwater Sounds Wrap-Up
    • All Things Vintage
    • Projects
    • The Pacific Northwest – PNW
      • Boating
    • Stories
      • Travel
  • Shop My Favorites
    • Home Décor & Kitchen Shopping Favorites
    • Shop for Your Garden
    • Shop My Amazon Store
    • Shop My Home
  • Meet Kim
  • Tour My Home
  • Contact Me

in Garden· Spring· Tips and Tutorials

How to Divide Dahlia Tubers in the Spring

  • Facebook
  • Email

Did you know that dividing your dahlia tubers every year has many benefits? I’ll show you my process for dividing and explain the advantages of splitting these dahlia root clumps annually.

dahlias in the summer

Dahlias are my favorite cut flower in the garden. I know it’s hard to pick just one favorite, and I have many runner-ups, but there is just something magical about them.

As an Amazon Associate, I earn from qualifying purchases. Affiliate links are used for your convenience. Read my full disclosure here.

I’m a self-taught hobby gardener, not a Master Gardener. Everything I share with you on my blog is my personal opinion and things that worked for me along the way.

dahlias in the garden

Why It’s Important to Divide Your Dahlia Tubers

This perennial plant grows from tuberous roots and is easily propagated by digging them up and dividing the roots. This will not only encourage the plant to produce more blooms but it will be healthier in the long run by separating the healthy tubers from those that are diseased or rotted.

Café au lait dahlias

It’s also a good idea to divide dahlias every year because of how quickly the tubers grow. If they get too large, they will rot or become too heavy to lift and store. Trust me, there has been a season or two when I’ve had trouble picking up a clump of dahlia tubers because it was too big for me to lift!

splitting dahlia tubers in the spring

Materials You Will Need to Divide

  • Clean pruners and/or sharp knife
  • Spading fork, shovel, or trowel
  • Tarp
  • Buckets
pink dahlias

When to Divide Your Dahlia Tubers

Dahlias are hardy only in gardening zones 8-11, so if you live in colder climates, you’ll need to dig up your tubers in the fall. If that’s the case, you have a choice of dividing the roots just before you store the tubers for winter, or you can divide them in the spring which is what I do.

white dahlias with a purple center

I divide my dahlia tubers in the spring, usually in April. I’m in gardening zone 8B with a last frost date of April 18th, so this works best for my climate. When planning when to divide, take into consideration your last frost date. Here are some benefits to splitting your tubers in the spring…

  • The eyes on the tuber are more visible in the spring. If you’re really timing it right, you will even see sprouts where the eyes are, making the process that much easier.
  • I’m able to discard any rotted or diseased tubers that haven’t made it through the winter.
  • My tubers in garden zone 8B stay in the ground, protected by mulch, so I don’t dig them up in the fall.

splitting dahlia tubers

Digging Up the Tubers

When digging the dahlia tubers out of the ground you will need to be very careful not to damage them. Use a pitchfork or shovel and gently dig around the dahlia clump and pull up with last year’s stock if possible. It works best if you’re able to have two people working together during the process.

dahlia tubers dug out of the ground

If you do end up breaking a tuber apart, there’s no need to worry. There is most likely an eye on one of the tubers that weren’t ruined.

You will need to wash off the tubers before dividing so you can see the eyes. Store them in a potting shed or garage for a few days to allow them to dry.


dahlia tuber clump

Dividing the Dahlia Tubers

Each dahlia division needs to have at least one eye and a fat tuber. Every dahlia tuber clump will usually have one large central tuber, the mother tuber, with smaller offshoot tubers that develop throughout the growing season.

Once the clumps have dried, carefully examine each dahlia tuber to see how they made it through the winter. These are the tubers I look to cut from the root clump…

rotted dahlia tuber that was dug up
  • Any damaged, rotted, or diseased tubers
  • Tubers that are small or with skinny necks and no eyes
  • The mother tuber because it’s already expended most of its energy. These offshoots usually have white or pink dots around the base of the stem rather than the typical growth eyes.

It is important to use sharp, clean pruners or a knife when cutting your root clumps. Using clean pruners will help to prevent passing any diseases to the tubers. Split the clump in half so the pieces are easier to work with. It’s really up to you whether to divide the sections even smaller, or into individual tubers. Keep in mind that every tuber must have an eye in order to be viable.

rotted dahlia tuber

I know that trying to find the eye on a dahlia tuber can be challenging, so I have shared a link with you on a great blog post by Gardens By Evelyn that helped me. Dahlia tuber eyes will never develop farther down the neck of the tuber than the collar. Before an eye has sprouted out, it tends to just look like a tiny bump or wart.

the eye of the dahlia tuber
Photo credit: Dahlias by Evelyn

The eyes are basically where the stem comes from the following year. So when dividing the tubers, it’s important to separate the clump into sections that include a part of the stem base with an eye and one or more offset tubers.

If you can’t find the eye on the tuber, place it in a moist and warm area for about a week. Once the time has passed, the eyes should begin to sprout which means they are healthy.


bees on dahlias

Planting the Dahlia Tubers

Dig a hole 4-6 inches deep and lay the tuber on its side, horizontally, with the growing eye facing up. Fill the hole with soil. Space the tubers between 12-18 inches.

Don’t water your newly planted tubers until you see the first green shoots coming up through the ground. Watering before any new growth is visible can cause the tubers to rot. Dahlias love being watered consistently through the growing season. After your dahlias are established, you should water your plants deeply 2-3 times a week for at least 30 minutes. I have a drip system that works really well.

And remember, slugs and snails LOVE dahlias so as soon as you see new growth popping out of the ground, you must use some sort of slug prevention. I use Sluggo which is safe for pets. I can’t tell you how many times I have had slugs eat the plant as it was just starting out.

dahlias in the cottage garden

For more information about growing dahlias including pinching and staking, read my blog post ALL YOU’VE EVER WANTED TO KNOW ABOUT DAHLIAS.

Leave me a comment if you have any questions about this process. Now let’s see more garden tips and tours from my friends.

Until next time,

Happy Gardening!

More Garden Inspiration

Make sure to visit my friends to see what they’re up to in their gardens. It’s always fun to see what’s happening in the other parts of the country.

Chas’ Crazy Creations | Gardening with Straw Bales Set Up

Life at Bella Terra | May Gardening in 9B

Stacy Ling Bricks ‘n Blooms | Early Spring in the Garden Tour


PIN AND SAVE ON PINTEREST

If you’ve enjoyed this blog post, please pin and share this on Pinterest.

how to divide dahlia tubers in the spring

SHOP FOR YOUR GARDENING NEEDS


Let’s Connect on Social Media

  • Follow me @shiplapandshells on Pinterest, Instagram and Facebook
  • Join my Facebook Gardening Tips & Tricks Group!

  • Facebook
  • Email

Filed Under: Garden, Spring, Tips and Tutorials

Stay Connected and Get all the Latest

Previous Post: « Saltwater Sounds Weekly Wrap-Up
Next Post: Saltwater Sounds Weekly Wrap-Up »

Reader Interactions

Comments

  1. Rachel Harper says

    03/31/2022 at 8:56 am

    Kim,
    Such helpful information. You make it sounds so easy. I might even try growing some.

    Reply
    • Kim says

      04/05/2022 at 3:24 pm

      You should definitely try to grow a few and see how you like them Rachel.

      Reply
  2. Tammy says

    03/29/2022 at 11:40 am

    Kim, this was so interesting. I only have grown Dahlias in container gardens. I am in Zone 7A. Your Dahlias are so beautiful. I cannot wait to see more of your flower gardens.

    Reply
    • Kim says

      04/05/2022 at 3:29 pm

      I’m getting excited to see more flowers start blooming myself! I think dahlias are beautiful in container gardens. Thanks for visiting Tammy!

      Reply
  3. Rachel Nevill says

    11/22/2021 at 10:33 am

    Can you plant the divided tubers immediately or should you wait for it to callus? Thanks!!

    Reply
    • Kim says

      04/05/2022 at 3:34 pm

      If you wash off the tubers before dividing so you can see the eyes you should store them in a potting shed or garage for a few days to allow them to dry before placing them back in the ground. There are times that I can see the sprouts already so I don’t need to wash them and I just put them back into the ground with no problems.

      Reply
  4. stacy says

    05/04/2021 at 12:46 pm

    I can’t wait to see your dahlias this year! I just planted a bunch today around the new garden. I hope they all do well. xo

    Reply
  5. Chas Greener says

    05/04/2021 at 7:05 am

    Wow, thank you so much for sharing how to do this! I’m sharing with my mom as I know she does this in her garden and will appreciate your awesome tutorial. Thanks for sharing and wonderful hopping with you.

    Reply
  6. Mary from Life at Bella Terra says

    05/04/2021 at 5:21 am

    Kim, I love dahlias but I thought I couldn’t grow them in Phoenix. I will need to research that as I am zone 9B and you stated they do grow in 8-11. Hmmm. I planted them one year and nothing came up so I’m guessing I did it wrong. I would LOVE to grow these. Great tutorial on dividing them. Now you have gotten me excited about this! Happy hopping with you.

    Reply

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

Meet Kim

Hi! I'm Kim. Welcome to my home & garden blog, Shiplap and Shells. We live in a small 1920 beach cottage in the Pacific Northwest and have spent the last 10 years renovating, reinventing, and adding character to our forever home. Read More…

Up to 30% off candles

Find what you’re looking for

Let's Connect

Stay up to Date

shop my home

  • My Blog
  • Shop My Favorites
  • Tour My Home
  • Meet Kim
  • Contact Me

Footer

Find What You’re Looking For

Follow Along

Disclaimer and Privacy Policy

Copyright © 2023 · Market Theme on Genesis Framework · WordPress ·