How to Harvest Dahlia Tubers in 5 Steps

One of the great qualities of dahlias is their ability to be harvested at the end of the season, stored over the winter, and used again the next year. It is an easy, simple process that has a high rate of success. 

In this guide, you will learn how to harvest your dahlia tubers properly in preparation for storing them, including how and when to dig up tubers.

 Step 1: When to Dig Up Dahlia Tubers

Although dahlias produce tubers starting in the springtime, you’ll want to wait until late in the season when the tubers mature to harvest them. This will ensure that they keep well and are successful when planted again the next year.

As a general rule, the longer the tubers are in the ground curing, the better chance they have of growing and thriving the next year. A good rule of thumb is to harvest right before the first hard frost, usually in the late fall.

Step 2: How to Cull and Label Your Dahlias

Before you start your harvest, take stock of your garden and throw away any weak-looking plants. This includes dahlias that didn’t produce superior flowers or those that had signs of disease.

The next step is to label varieties. This can be as simple as writing the name of a specific dahlia variety on a popsicle stick or on the stake that the plant is attached to.

This will save you a lot of time in the long run, as dividing and storing will be a breeze when you know exactly which variety you are dealing with.

Step 3: How and When to Cut the Stalks

When cutting the stalks of your dahlias in preparation for harvesting the tubers, be sure to leave a few inches of the stalk for easy handling.

Most gardeners recommend cutting the stems a couple of days before digging. This causes the eyes to come out and makes the process of dividing the clumps easier. However, there is a risk of water getting into the stem and causing rot.

Covering the cut stems with aluminum foil can help to prevent water from entering the plant and ruining the tubers.

Step 4: How to Dig Up Dahlia Tubers

This is the most important part of harvesting dahlia tubers. You’ll want to dig and handle the clumps gently, as their necks are fragile.

To harvest tubers, dig all around the dahlia plant about 10-12 inches away from the main stem. When all four sides have been loosened, insert a shovel or pitchfork under the tubers and gently lift them out of the ground.

Remove any clumps of soil that are hanging on to the tubers, then turn them upside down to drain out any remaining water from the stem.

Step 5: How to Clean Dahlia Tubers

The last step in harvesting your dahlia tubers is to clean them. A garden hose or sink are two of the easiest ways to wash the dirt off of them.

The reason you want to remove the soil is that there are microorganisms in it that can be detrimental to the tuber while it is in storage.

Now you are ready for cutting and dividing!