Introduction
Finding a dahlia variety that perfectly matches your garden style is one of the most rewarding parts of being a gardener. Whether it is a giant dinnerplate dahlia or a dainty pompon, these plants often become the stars of the summer show. At Longfield Gardens, we know how much joy these blooms bring, and it is only natural to want to save those tubers so you can enjoy them again next year. (longfield-gardens.com)
If you live in a region where the ground freezes, you must dig up your dahlia tubers and store them indoors for the winter. One of the most common questions we hear from home gardeners is whether paper bags are a safe and effective choice for this process. This guide is for anyone looking for a simple, reliable way to keep their favorite flowers safe until spring. (longfield-gardens.com)
We will cover the benefits of using paper bags, how to prepare your tubers for storage, and the best environment to keep them healthy. By the end of this article, you will have a clear plan for overwintering your dahlias with confidence. Storing your own tubers is a wonderful way to grow your garden collection year after year. (longfield-gardens.com)
Why Paper Bags Are a Great Choice for Dahlias
The short answer is yes, you can absolutely store dahlia tubers in paper bags. In fact, many experienced gardeners prefer this method over plastic containers or wraps. The primary reason paper bags work so well is breathability. Dahlias are living organisms even when they are dormant, and they need a specific balance of moisture and air to survive the winter.
Paper is a natural material that allows a small amount of air to circulate around the tubers. This circulation is vital because it helps prevent the buildup of moisture that leads to mold and rot. At the same time, a paper bag provides a dark, protected environment that keeps the tubers from drying out too quickly.
If your storage area is naturally a bit damp, such as a traditional root cellar or a cool basement, paper bags act as a buffer. They can absorb a small amount of excess humidity from the air without passing it directly onto the plant. This makes paper bags one of the most forgiving tools for a beginner to use.
Key Takeaway: Paper bags are a top choice for dahlia storage because they breathe. They help prevent rot by allowing air circulation while still protecting the tubers from light and extreme temperature shifts.
Timing Your Harvest for Success
Successful storage starts long before you reach for a paper bag. The timing of when you dig up your tubers is the most important factor in their survival. In most parts of the United States, we recommend waiting for the first frost of the autumn.
A killing frost will turn the dahlia foliage black and limp. This might look a bit sad, but it is actually a helpful signal. The frost tells the plant to stop growing leaves and start sending all its energy down into the tubers for the winter. This process helps the tubers "cure" and prepares them for their long winter sleep.
After the foliage turns black, we suggest waiting about 5 to 7 days before digging. This short waiting period allows the tubers to develop a slightly tougher skin, which makes them more resistant to bruising and dehydration during storage. If your weather forecast predicts a hard freeze where the ground itself will freeze solid, you should dig them up immediately, even if a frost hasn't hit yet. (longfield-gardens.com)
How to Dig and Clean Tubers for Storage
When you are ready to dig, the goal is to be as gentle as possible. Dahlia tubers are often described as looking like a bunch of sweet potatoes, and they are surprisingly fragile. The "neck" of the tuber—the part where it connects to the main stem—is especially delicate. If this neck breaks, the tuber may not be able to sprout next year.
- Loosen the soil: Use a garden fork or a shovel to gently loosen the soil about 12 inches away from the main stem.
- Lift carefully: Gently lift the entire clump out of the ground. Avoid pulling on the stems, as this can snap the tubers off the main body.
- Remove excess dirt: Shake off the large clumps of soil. You do not need to make them perfectly clean, but removing the bulk of the dirt makes it easier to see what you are doing.
- Trim the stems: Cut the main stalks back so only about 2 to 4 inches of stem remain above the tubers.
Once the tubers are out of the ground, some gardeners like to wash them with a garden hose. This is a personal preference. If you have heavy clay soil, washing makes it easier to inspect the tubers for damage. If you have sandy soil, a simple brush-off is usually enough. (longfield-gardens.com)
The Importance of Curing Before Bagging
Before you put your dahlias into paper bags, they need a short period of "curing." Curing is just a fancy word for letting the tubers air-dry. If you put wet, freshly dug tubers directly into a bag and close it up, you are creating a perfect environment for mold to grow.
Find a cool, dry place that is protected from direct sunlight and frost. A garage or a covered porch works well. Lay the tubers out on a piece of cardboard or a newspaper. Let them sit for 1 to 3 days until the surface of the skin feels dry to the touch and any remaining soil has turned to dust.
During this time, the skin will continue to toughen up. This is a great time to inspect the clump. If you see any tubers that are mushy, broken, or look like they are rotting, trim them away with a clean pair of garden snips. Starting with only healthy, firm tubers is the best way to ensure success in the spring. (longfield-gardens.com)
What to do next:
- Set up a drying station in a frost-free area like a garage.
- Lay tubers in a single layer so they aren't touching.
- Wait 24–72 hours until the skins feel dry and papery.
- Discard any tubers that feel soft or look diseased.
Packing Your Paper Bags Correctly
Once your tubers are dry and cured, it is time to move them into their winter homes. You can use standard brown lunch bags for individual tubers or larger grocery-style bags for full clumps. Using paper bags also makes organization very easy. You can write the variety name, color, and height directly on the bag with a marker.
You have two main options for how to pack the bags: the "dry" method and the "medium" method.
The Dry Method
In the dry method, you simply place the clean, dry tubers into the paper bag and fold the top over. This works best if you have a storage area with high humidity, like a damp basement. The paper protects the tuber, but there is no extra material to hold onto moisture.
The Medium Method
Most gardeners find more success by adding a storage medium inside the paper bag. A storage medium is a loose material that helps regulate moisture levels. Common choices include:
- Coarse Vermiculite: A mineral that holds a tiny bit of moisture but stays very airy.
- Peat Moss: A classic choice that helps prevent the tubers from drying out too much.
- Wood Shavings: The kind used for pet bedding is inexpensive and works well to cushion the tubers.
To use this method, put a few inches of your chosen material into the bag, nestle the tuber inside, and cover it with more material. This "blanket" protects the tuber from shifting around and provides a buffer against the dry winter air.
Finding the Best Storage Spot
The success of your paper bag storage depends heavily on where you put the bags. Dahlias need a "Goldilocks" environment: not too hot, not too cold, and just the right amount of moisture.
The ideal temperature for storing dahlia tubers is between 40°F and 45°F. If the temperature stays consistently above 50°F, the tubers may think it is spring and try to start growing, or they might simply shrivel up and die. If the temperature drops below freezing (32°F), the water inside the tubers will freeze, turning them into a mushy, black mess when they thaw.
A cool basement, an unheated crawl space, or a corner of an insulated garage are usually the best spots. Keep the bags off the floor by placing them on a wooden shelf or inside a cardboard box. Concrete floors can be very cold and may draw moisture out of the bags.
Safety Note: Dahlia tubers are not edible and can be harmful if eaten by pets or children. Always store your bags in a place where curious pets or toddlers cannot reach them.
Monitoring Your Tubers Through the Winter
Gardening doesn't totally stop in the winter; it just moves indoors. One of the biggest mistakes gardeners make is "setting and forgetting" their stored tubers. We recommend checking on your paper bags once a month.
When you do your monthly check, look for two things: rot and shriveling.
If a tuber feels mushy or has a foul smell, it is rotting. Remove it immediately and throw it away so the rot doesn't spread to the healthy tubers in the bag. If the paper bag feels damp or has visible mold, move the tubers to a fresh, dry bag and consider a slightly drier storage spot.
If the tubers look very wrinkled or feel lightweight and "hollow," they are drying out. You can fix this by lightly misting the storage medium (the peat moss or shavings) with a spray bottle of water. Do not soak them; you just want to add a tiny bit of humidity back into their environment. (longfield-gardens.com)
Key Takeaway: A quick monthly check is the best insurance policy for your dahlias. Catching a single rotting tuber early can save the rest of your collection from ruin.
Preparing for Spring Planting
As the days get longer and the ground begins to thaw, your dahlias will naturally start to wake up. You might see small pink or white "eyes" (buds) beginning to sprout on the tubers inside your paper bags. This is an exciting sign that your storage was a success!
Don't rush to plant them in the ground too early. Dahlias love warm soil and are very sensitive to spring frosts. We recommend waiting until the soil temperature reaches about 60°F and all danger of frost has passed. This usually happens around the same time you would plant tomatoes in your area. (longfield-gardens.com)
If you want an early start, you can "pot up" your tubers indoors about 4 to 6 weeks before the last frost date. Take them out of their paper bags and plant them in pots with slightly damp potting soil. Keep them in a sunny window or under grow lights, and you will have healthy, green plants ready to go into the garden as soon as the weather warms up.
Common Myths About Dahlia Storage
When searching for advice online, you might find some "hacks" that sound too good to be true. One common myth is that you can store dahlias in the refrigerator. While the temperature might be right, most refrigerators are actually very dry environments that will shrivel a tuber in weeks. Additionally, some fruits (like apples) release gases that can prevent dahlias from sprouting.
Another myth is that you must use fungicide powders on every tuber. While a fungicide can help if you have had a lot of rot in the past, most home gardeners find that proper cleaning, curing, and the use of breathable paper bags are enough to keep their plants healthy.
At Longfield Gardens, we believe in keeping gardening simple. By focusing on the basics—proper timing, drying, and a cool storage spot—you can achieve great results without complicated equipment or expensive chemicals. (longfield-gardens.com)
Comparing Paper Bags to Other Methods
While we are focusing on paper bags, it is helpful to know how they compare to other popular methods like plastic wrap or plastic bins.
- Plastic Wrap: Some gardeners wrap individual tubers tightly in plastic wrap. This is great for saving space and preventing the spread of rot, but it requires the tubers to be perfectly dry before wrapping. It offers zero breathability, which can be risky for beginners.
- Plastic Bins: Using a plastic tub with a lid is common. However, these bins trap moisture very effectively. If you use a plastic bin, you usually need to leave the lid slightly ajar or drill holes in the sides to prevent the tubers from "sweating" and rotting.
- Cardboard Boxes: Cardboard is very similar to paper bags in its benefits. It is breathable and dark. Many people use a combination of both—putting paper bags inside a larger cardboard box for extra insulation.
For most home gardeners, the paper bag method offers the best balance of ease, affordability, and plant health. It is a time-tested technique that works across many different climates.
Troubleshooting Common Storage Issues
If you find that your tubers didn't survive the winter, don't be discouraged. Gardening is a learning process, and every storage environment is unique.
If your tubers were mushy, the most likely cause was too much moisture. This could mean they weren't cured long enough, the storage medium was too wet, or the room was too humid. Next year, try a longer curing period or use a drier storage medium like wood shavings.
If your tubers were shriveled and dry, they likely lost too much moisture. This often happens in modern basements with furnaces that dry out the air. Next year, try adding more peat moss to your paper bags or placing the paper bags inside a plastic bin with the lid left halfway open to trap just a bit more humidity.
One change at a time is the best way to troubleshoot. If you change your digging time, your curing time, and your storage spot all at once, you won't know which change made the difference. (longfield-gardens.com)
Conclusion
Storing dahlia tubers in paper bags is a practical and rewarding way to preserve your favorite garden varieties. This method takes advantage of the natural breathability of paper, helping to keep your tubers dormant and healthy throughout the cold winter months. By waiting for the frost, curing the tubers properly, and finding a cool, dark spot for your bags, you are setting yourself up for a spectacular garden next summer. (longfield-gardens.com)
We are here to help you succeed, and we stand behind the quality of our plants with a 100% guarantee. Whether you are a first-time dahlia grower or a seasoned pro, the satisfaction of seeing those first green shoots emerge in the spring makes the winter effort well worth it.
- Wait for a killing frost to signal the plant to go dormant.
- Cure tubers for 1–3 days in a cool, dry place before bagging.
- Use paper bags with a medium like peat moss or vermiculite for the best moisture balance.
- Check your storage monthly and remove any rotting tubers immediately.
"The secret to beautiful summer dahlias often lies in how well they sleep during the winter. A simple paper bag and a cool corner are sometimes all a gardener needs to keep the magic alive."
For your next garden project, consider adding new colors and textures to your collection. We invite you to explore our premium dahlia tubers at Longfield Gardens and start planning your most beautiful season yet. (longfield-gardens.com)
FAQ
Can I reuse paper bags from the grocery store for dahlia storage?
Yes, as long as they are clean and dry. Make sure there are no food residues or oils on the bags, as these can attract pests or encourage mold growth during the winter. (longfield-gardens.com)
Should I divide my dahlia clumps before putting them in paper bags?
You can divide them either in the fall or the spring. Many beginners find it easier to store the whole clump in a large paper bag and wait until spring to divide them, as the "eyes" or buds are much easier to see once the plant starts to wake up.
How many tubers can I put in one paper bag?
It is best to keep them in small groups. For lunch-sized bags, one or two tubers are ideal. For larger grocery bags, you can store two or three clumps. Avoid packing them too tightly, as you want air to be able to reach each tuber.
Is it okay to use newspaper instead of paper bags?
Yes, wrapping tubers in several layers of newspaper is very similar to using a paper bag. It provides breathability and darkness. However, paper bags are often easier to manage and much simpler to label with a marker.
