From Soil to Spring: How to Save Your Dahlia Tubers for Next Season’s Bold Blooms

How to Tag, Dig, Divide, and Store Dahlia Tubers for Winter: A Step-by-Step Guide

It has been a wonderful dahlia season, but, it is now coming to an end as the end of season frost is almost here.  Dahlias are cherished for their blooms, but as they’re not frost-hardy, they need special care when winter approaches. If you want your dahlias to flourish again next season, you’ll need to properly tag, dig, divide, and store their tubers. Here’s a comprehensive guide, including two methods for storing dahlia tubers: using vermiculite and/or the saran wrap method.

Tagging Your Dahlias

 Before frost arrives, it’s important to tag each plant. This helps you keep track of the different varieties when it’s time to plant them again next year.

• How to tag:   

We use colored flagging tape and attach it to the base of the stem while the plant is still standing. Include the variety name or any specific traits.

Cut down the dahlia plant:

 Using a loppers, cut the stem down to 4”-6” above the ground so you have a handle to move the tuber clump around prior to dividing the tubers.

Digging Dahlia Tubers

Once the dahlia plants have been cut, let the tubers cure in the ground for 1-2 weeks as this allows the tubers to firm up so they store better and the eyes to begin to develop so they are easier to see when dividing.  Now, it is time to dig up your dahlia tubers.

Using a garden fork or shovel to dig around the plant, leaving a wide berth to avoid damaging the tubers.  Gently lift the tuber clump from the soil, shaking off excess dirt.

Be careful not to break or nick the tubers, as damaged tubers are prone to rot during storage.

Rinse the dahlia tubers to remove all excess:

With a hose, rinse the tubers to remove soil.  

Dividing Dahlia Tubers

 Dividing tubers helps maintain plant vigor and gives you more dahlias to plant next year.

You can divide your tubers either right after digging or in the spring before planting.  We divide in the fall right after digging the tubers as they require significantly less space when stored as tubers vs as a tuber clump.

1.  After digging and rinsing, we divide our tubers within 2-3 hours of rinsing.  We do not want the tubers to desiccate and to begin to shrivel.  So, whatever we dig, we rinse, divide, and store all in the same day.  We tend to do this in batches of 10-25 so we are able to finish this work all in one day.

2. Using a sharp, sterilized(10% bleach to water) shears or pruning shears , discard any soft or damaged tubers and remove all small roots to “clean up” the tuber clump.  

3.  Then begin carefully dividing the tubers, ensuring that each division has at least one “

Storing Dahlia Tubers

Proper storage is key to keeping your dahlia tubers healthy through the winter. Here are two popular methods: using vermiculite and the saran wrap method.

Method 1: Storing Tubers in Vermiculite 

Vermiculite is a mineral that retains moisture while providing aeration, making it an ideal medium for storing tubers.  We use this for our medium to large tubers as they tend to store well with this bulk method.  Lightly moisten the vermiculite so there is some humidity in the vermiculite.

• How to store:

1. Let your tubers dry for 2-3 hours in a cool, dry place after dividing.  We want the tubers to be dry but don’t wait too long or they will start to desiccate.

2. Fill a storage box with a few inches of vermiculite.

3. Place the tubers in the box, ensuring they don’t touch each

4. Cover the tubers with another layer of vermiculite so the tubers are completely covered.

5. Store the box in a cool, dark place like a basement or garage, where the temperature stays between 40-50°F (4-10°C). Check on them periodically through the winter to ensure they aren’t drying out or rotting.

Method 2: Storing Tubers Using Saran Wrap

The saran wrap method is a simple way to prevent tubers from drying out while also protecting them from excessive moisture.  We use this on all our thinner tubers as they tend to dry out in the vermiculite.  Think pencil size tuber necks.

 • How to store:

1.  Let your tubers dry for 2-3 hours in a cool, dry place after dividing.  We want the tubers to be dry but don’t wait too long or they will start to desiccate.  We also dip our tubers in cinnamon as it has anti fungal properties.

2. Wrap each tuber individually in a layer of plastic wrap, ensuring it’s snug but not too tight. 

3. Store the wrapped tubers in a box or paper bag, in a cool, dark place.  We use the same boxes that we use for the vermiculite.

4. Check the tubers occasionally for any signs of mold or rot, and remove any affected tubers immediately.

Tips for Success

• Label your storage containers: Make sure you label the varieties as you store the tubers. We label the outside of the box so it is easy to identify and also add the flagging tape to the inside of the box. This will make it easy to know what you’re planting in the spring.

• Check for rot or dryness: Over the winter, inspect your stored tubers every few weeks. Remove any that show signs of rot or have dried out too much.

• Keep the temperature stable: Avoid storing tubers in areas that experience temperature fluctuations, which can lead to premature sprouting or freezing.  

Conclusion:

Tagging, digging, dividing, and storing dahlia tubers properly will ensure they survive the winter and return next season with vibrant blooms. Whether you prefer the vermiculite method or the saran wrap method, both approaches can protect your dahlias from rot and drying out. With proper care, you’ll enjoy beautiful, thriving dahlias year after year!