The Best Practices for Storing Dahlia Tubers in the Garage Over Winter

This blog post is about my favorite (and perhaps weird) way of storing dahlia tubers. I’ll talk about how I dig up my dahlias, how most people store their tubers for the winter, and how this strange method works below.

Dahlias are amazing. They bloom all summer, from the beginning of summer (usually in July or August) until the first frost. You plant them in the spring. The only problem with dahlias is that they need extra care over the winter so they can bloom again the following year. There are people who don’t care about this, though, and they buy and plant dahlias every year. But if you want to get the most out of your money, this article will show you a simple (and maybe even strange) way to keep your dahlias during the winter.

Although dahlias are technically perennials, they are only hardy to USDA Zone 8, which is 10 to 15°F (-12 to -9 °C). They are also very prone to rotting. From what I’ve heard, dahlias die more often from wet winter soil and poor drainage than from the cold. Make sure you plant them in a spot that drains well.

The weather can do crazy things sometimes. Your dahlias may be safer in the winter if you mulch them and plant them in a well-drained area, but that’s not a promise. You can be sure that your dahlias will make it through the winter if you dig them up and store them.

As autumn winds down the dahlia growing season in cooler climates, responsible gardeners must turn their attention to proper end-of-year tasks This includes digging up and storing tender dahlia tubers over the winter months when freezing temps can damage or destroy them Fortunately, the ideal storage conditions are easy to recreate in a typical garage. With a little preparation, your garage can become the perfect place for preserving dahlia tubers until spring planting.

Why the Garage Works Well for Storing Dahlias

The key factors for successful dahlia tuber storage are steady cool temperatures and avoiding freezing Garages provide an easily accessible spot that hits the sweet spot of 40-50°F during the dormant season Here’s why garages excel at safeguarding tubers

The enclosed structure protects from hard freezes and temperature swings.
Concrete floors offer excellent cold storage staying just above freezing.
Most garages maintain cooler temps than the main house.

Convenient access lets you readily check tubers during winter.
Space allows flexibility in storage methods used.

Preparing the Garage for Dahlia Tuber Storage

A few simple preparation steps can make your garage an even better overwintering spot:

Install insulation to moderate any temperature extremes.
Seal cracks and openings that allow rodents or excess dampness.

Place tubers up on shelves or blocks to avoid direct cold from the concrete floor.
Use space heaters very temporarily if temps dip below ideal range.
Keep garage somewhat dark to keep tubers dormant.

Storing the Tubers in the Garage

There are several effective methods to store the dormant tubers within the stable conditions of the garage:

Pack clumps or individual tubers in slightly moist peat, sawdust, or shredded paper.

Place in open boxes, crates, or mesh bags with air circulation.
Wrap each tuber separately in plastic wrap, tissue, or newspaper.
Hang mesh bags filled with packing material and tubers from rafters or shelves.

Bury in shallow flats or trays filled with sand, vermiculite, or compost.

Maintenance During Garage Storage

A small amount of maintenance helps ensure tubers stay healthy:

Periodically check for any rotting tubers and discard immediately.
Lightly mist clumps with water if packing media seems too dry.
Move containers around to even out garage temperature variations.

Repack if packing materials start to break down or compress over time.
Keep a look out for rodents, household pets disturbing tubs.

What to Avoid When Storing in the Garage

Some common garage variables can cause issues for stored tubers:

Drastic temperature fluctuations from vehicle exhaust, appliances.
Damp concrete acting as a heat sink pulling warmth from tubers.

Excess moisture from rain or snow if garage isn’t fully sealed.
Rodents seeking food source if garage has access holes.
Stacking containers tight against exterior walls that get very cold.

Timing for Putting Tubers Into Garage Storage

Harvest tubers after first frost once foliage is browned and shriveled.
Allow freshly dug tubers to air dry for 1-2 weeks protected from frost.
Move to garage storage anytime from October through December.

Start checking for eyes 6-8 weeks before spring planting time.

Transitioning Tubers Back Out for Spring Planting

Pull stored tubers from garage 1-2 months before planting outdoors.
Move to a warmer area around 65°F to initiate sprouting if not already eyed up.

Pot up sprouted tubers and grow on until hardened off for transplanting.
Time planting newly awakened tubers in garden to avoid any frost damage.
Provide temporary cover or move pots indoors if cold snaps occur after planting out.

With a bit of planning and attentive care, the humble garage can become your dahlia tubers’ winter sanctuary. Follow best practices and they will reward you with vigorous growth and spectacular flowers when warm weather returns.

How Most People Store Dahlias in Winter

There are many different ways to store dahlias. For instance, some prefer to wash them off immediately after digging the plants up. Many people divide them immediately, while others store the whole plant. Tubers can optionally be dipped in a diluted bleach solution, or dusted with sulphur powder to prevent rotting. The potatoes are then usually kept in something damp and clean, like peat moss, shredded paper, or cedar shavings. Some individually wrap the tubers in plastic saran wrap. These are great methods and are preferred by many experts in the dahlia world.

The dry storage technique is what I have started calling a technique I stumbled upon by accident. It works, and is perhaps the easiest method of storing dahlia tubers.

The Dry Storage Technique

First, cut the stems to five or six inches above ground level. Next, dig the dahlia plant out of the ground. Use the stems to pick up the plant and shake the excess dirt off. Then use your fingers to scrape away the excess dirt clumped between the individual tubers. Lastly, place the whole clump into a cardboard box or plastic crate and place in storage. I store them in my basement. You could also use a garage, attic, barn, spare room, or closet, as long as the temperature stays between 40 and 50 °F (5 and 10 °C).

I bring my garden hose down the stairs and into the basement two or three times a winter. Next, I use the “mist” setting on my regular garden hose nozzle to make the tubers wet. This keeps the dirt from drying out too much and coming up. They are pretty dry most of the time, though.

Digging and Storing Dahlias. A “how to” masterpiece theater

FAQ

Can you store dahlias in an unheated garage?

The ideal temperature is around 40-50 degrees. An attached garage is usually safe. Unheated outbuildings typically will freeze and aren’t a good choice for storage.

What is the best container to store dahlia tubers in?

The key to successfully storing dahlia tubers for the winter is making sure they stay dry, have good air circulation and are in a cool, dark spot. You can store the tubers in a variety of containers – milk crates, plastic bins, paper bags, and cardboard boxes all do the trick. You may choose to pack them in peat moss.

Can you store dahlia tubers in ziploc bags?

I usually fill gallon Ziploc bags with peat moss, dahlia tubers, and plastic labels for keeping track of the cultivars. I try to keep the individual tubers from touching to protect them from each other in case one starts to decay.

Where is the best place to store dahlia tubers?

Store Somewhere Cool Place your dahlia tubers in a cool, dark location for the winter. Basements, unheated garages, and closets are ideal for dahlia storage provided that the space remains frost-free. Ideal storage temperatures should range between 40-50 F (4-10 C) with approximately 90% humidity.