How can I tell if my dahlia tubers are dead?

QUESTION: How can I tell if my dahlia tubers are dead? I’ve had them sitting around a while and I am wondering if I can still plant them. They still look like a root. – Willamette G

JENNIFER POINDEXTER AT GARDENING CHANNEL REPLIES: There are a few signs that your dahlia tubers may be dead. If your tubers have a bad smell, are soft, spongy, or have mold on them, chances are they’re no longer viable.

Also, if you notice that your tubers are dried out and don’t appear smooth and full, these are also signs they could be dead.

When in doubt, you may always try the pre-sprout method to see if your tubers are still alive. You do this by placing the tuber in a sealable sandwich bag.

Add nutritious soil to the bag and spritz it with water. From there, leave the bag unsealed and place it in a sunny location.

Within a month to six weeks, you should see your tubers wake-up and form sprouts. This is also a great way of getting a jump on the growing season.

If you’re concerned about your tubers remaining viable, it’s important to understand how to properly store them.

Over the winter months, store your dahlia tubers in a location that’s dry, cool, dark, and has adequate airflow.

It’s important to store the tubers, so they aren’t stacked on each other and there’s room for air to circulate all around them.

One suggestion is to wrap your dahlia tubers in peat moss or straw and place them in a vented crate. This should stop the skins of the tubers from touching while allowing adequate airflow.

Take these pointers into consideration when storing your dahlia tubers overwinter. Also, utilize these tips when deciding whether or not your dahlia tubers are still viable after winter storage.

If they still look plump, have no odor, and have nothing growing on them, they should be fine. If your tubers seem questionable, pre-sprouting is an excellent way to find out if they’re viable while also jump-starting the growing process.

Hopefully, these tips can help you enjoy dahlias around your home and garden each growing season.

Overwinter and Store Dahlia Tubers Checklist

Begin guide after a killing frost occurs:

• Cut back plants to 2-4 inches (3-4 days after frost).
• Cure dahlia plants in the ground for approximately a week.
• Carefully dig up dahlia plants.
• Clean tubers by removing dirt. Cut stems back to the root.
• Wash if needed and let dry 24 hours.
• Store in a cardboard box, ideally in a cool, dry location. Use a base layer of vermiculite, peat moss or wood shavings. After placing the tubers in the box, apply a top layer of the same. Prevent and check for moisture. 

Learn More About Growing Dahlias

https://plants.ces.ncsu.edu/plants/dahlia/

https://extension.uga.edu/publications/detail.html?number=C576&title=dahlias

https://s3.wp.wsu.edu/uploads/sites/2086/2014/05/dahlias1.pdf