Why Digging Up Dahlia Tubers in Fall is Key to a Stunning Spring Garden

 

Dahlias have become a favorite among flower gardeners for their stunning, multi-colored blooms that brighten up gardens all summer and fall. However, ensuring your dahlias perform year after year and that next year’s flower garden is even better than this year’s requires some planning in Fall to ensure you are properly prepared for Spring.  This essential step not only protects your plants from frost but also offers valuable insights into your garden, helping you plan and improve for the following spring. And if you are new to growing dahlias, just skip the first four steps and start your planning on step 5.  You don’t necessarily have to do these steps as it is your dahlia journey and you can do the bare minimum or you can follow these steps to start to feed your passion and then take it from there!  With that said, lets talk through some of the steps you should consider.

1. Protecting Tubers from Frost Damage

Dahlias are native to warm climates, so their tubers are highly susceptible to frost and winter weather. In many regions, the first frost arrives in late fall, which can kill the plants and if the soil temperature drops to below freezing at the depth of the tubers they will freeze and then rot and can no longer be replanted for next springs blooms. By digging up the tubers in Fall, before the cold winter temperatures arrive(I begin to get concerned on nights with temperatures below 25 degrees), you can ensure the tubers remain viable and healthy for the next growing season.

2. Dividing Tubers for More Blooms

Fall is a great time to divide the dahlia clumps into individual dahlia tubers. Over the summer, the tubers multiply, and dividing them not only rejuvenates the plant but also allows you to propagate more dahlias. Each healthy tuber can produce a new plant, resulting in even more blooms for you next spring!  Imagine that favorite bloom that you have an instead of having one plant you have 3 or 5 or 7

 

3. Storing Tubers for Winter Dormancy

 Once dug up, the tubers can be stored in a cool, dry place where they can go dormant over the winter.  Proper storage prevents rot, mold, and other issues that can arise when tubers are left exposed to cold, wet conditions in the ground.  Storage of dahlia tubers is one of the biggest challenges in growing dahlias.  While you can choose to buy new dahlia tubers every year and skip the hassle of digging, dividing, and storing dahlia tubers, a good way to save money and multiply your stock is to learn these steps.  We will be writing a blog in the next week or two sharing how we dig, divide, and store tubers here at Pedaling Petals.

4. Assessing Tuber Performance: Know What Worked and What Didn’t

When you dig and divide your dahlia tubers in fall, you gain the opportunity to evaluate their health and growth. Some dahlias may have thrived and produced large, healthy tubers, while others may have struggled and produced smaller, less viable ones. This is a crucial learning moment for understanding which varieties performed well in your garden’s conditions—whether due to soil health, virus, insects, dahlia variety, or other environmental conditions. It gives you a chance to identify which plants are worth propagating and which ones may need a different approach next year.

This evaluation allows you to refine your future planting strategies. You can take notes on which dahlias were most productive and decide to either grow more of those varieties or experiment with new ones. Keeping track of this information ensures you are continuously improving the quality and success of your garden.

5. Expanding Your Collection: Trade and Buy New Varieties

 Digging up your dahlia tubers also gives you a clear inventory of what you have—and this information can help you diversify your collection.  As dahlias grow, they form multiple new tubers that can be divided and replanted, resulting in a surplus of certain varieties. If you have extra tubers of a favorite variety, you can trade with other gardeners or sell them to expand your collection with new or rare varieties you may not have.

 Likewise, assessing your tuber inventory lets you know what you’re lacking.  Do you have too many of one color and not enough of a different color?  Too many large blooms and not enough small blooms?  Or maybe you have seen a favorite on social media or from one of your friends and you want to give it a try.  Some of the most fun and excitement in growing dahlias is what do I want to grow next summer and creating your wish list!  In fact, it can get addicting!  There are dahlia growers groups on Facebook where people are willing to trade varieties that have that interest you for varieties you have and that can be a great way to meet fellow dahlia growers and check varieties off your wish

It is also the perfect time to create your list of varieties you wish to buy as many of the dahlia tuber sales start at the beginning of the year and hard to find varieties often sell out very quickly.  So, if you plan to buy tubers it is wise to plan ahead and fall is a great time to do that.

This way, you’re constantly improving the aesthetic of your garden, introducing new forms, colors, and shapes that can add to the diversity and visual appeal of your spring and summer 

6. Preparing you garden soil

Digging up your dahlia tubers in Fall doesn’t just benefit your dahlia tuber inventory and prepare you for dahlia tuber trades and dahlia tuber sales—it’s also an excellent opportunity to prepare your soil for winter. Once the tubers are removed, the garden beds can prepped for planting cover crops, doing a soil test, amending with organic matter, and amending with the appropriate nutrients.  We encourage the use of cover crops, such as clover, winter rye, or field peas, protect the soil from erosion, add nutrients back into the soil, and improve its structure over the winter months. This soil regeneration ensures that your dahlias and other plants will have rich, fertile soil to grow in when the spring season arrives.

By digging up the tubers, you also remove any decaying plant matter that could harbor pests or disease, reducing the risk of problems in the next growing season. With a well-prepared, nutrient-rich soil, your dahlias will have a healthy environment for root development, ultimately leading to stronger plants and

Digging up dahlia tubers in fall is a crucial step for anyone looking to grow a stunning spring garden. Not only does it protect the tubers from frost, but it also allows you to assess performance, trade or purchase new varieties, and prepare your soil for cover crops. Each of these actions contributes to a thriving, colorful garden that gets better year after year. By taking care of your dahlia tubers now, you’re setting the stage for a breathtaking display of blooms when warmer weather returns.