THE NEED FOR WINTER STORAGE
Dahlia tubers are very cold sensitive and will need to be dug and stored in a cool but frost free storage area during the winter months. Fortunately, there are many acceptable storage methods for over wintering dahlia tubers. If you are new to dahlia growing or if your method is not working or easy enough you may wish to try this relatively new, but well tested, method that uses Saran wrap or any other plastic wrap film that is readily available from your local supermarket.
Storage of dahlia tubers using plastic wrap meets the primary goal of preserving the tubers in as close to as when dug condition. This method uses no additional storage medium such as the traditional vermiculite, peat moss, wood shavings or sand. The thin plastic wrap used in this method does provide for some air exchange but not to the extent that will allow the bulb to desiccate.
This method of storage does not require any changes in the digging, washing and dividing of your dahlia tubers.
DISINFECTING DAHLIAS
Cut surfaces on freshly divided tubers heal over rather quickly after surface drying. The cut surfaces are a logical entry point for bacteria and fungi spores so it is recommended to use either a liquid fungicide such as Daconil or a powdered fungicide such as Captan. Garden sulfur flour is highly effective and very inexpensive. If you decide to use Daconil or Captan, you should follow the directions for use as provided by the manufacturer. If you should use sulfur flour it is recommended that you add ½ cup of sulfur to 4 cups of coarse peat, vermiculite or dry play sand in a medium sized plastic bag. A plastic shopping bag will work nicely. The divided dahlia tubers can be placed in the plastic bag and gently mixed so as to cover the tuber with a thin layer of sulfur flour. Care should be exercised so as to not breath the dust of Captan, sulfur flour or vermiculite (which can contains asbestos fibers).
Small quantities of tubers can have their cut surfaces disinfected using Lysol spray, a product that has been shown to provide excellent protection from spoilage caused by bacteria and fungal contamination.
Treated tubers will be ready for plastic wrap storage as soon as the surface of the tuber has dried, generally within several hours. Tubers that are not packed promptly will begin to desiccate resulting in lowered tuber quality and greater loss over the winter months.
The plastic wrap storage method is highly effective for small tubers and tubers with long, thin necks. These types of tubers frequently tend to rot or dry out with other storage methods.
PLASTIC WRAP YOUR TUBERS
Cut off a length of plastic wrap about 50 cm (two feet) in length and lay it flat on a counter or table surface. At one end of the plastic wrap place one of the tubers. Roll the tuber so that it is completely covered with a single layer of plastic. Then add another tuber and roll over one complete turn. Continue in this manner until you have rolled 5 or six tubers into a neat bundle being careful so that no two tubers are touching and to cover both ends of the tubers with the plastic wrap. Be certain that no tuber is touching another as plastic wrap should separate each tuber. Masking tape can be used to hold the plastic film in place. The name of each variety can be written on the masking tape with a permanent pen for easy identification.
Extra long tubers may need to be wrapped with the tuber parallel to the edge of the wrap so as to cover the entire length of the tuber. This is especially important when the tuber length is close to the width of the plastic wrap. Wrapped and marked bundles of tubers should be stored in a storage container such as a corrugated box or bulb crate for the duration of the storage period at a temperature as close to 4 - 8 degrees C (40 – 46 degrees F) as possible. Tubers should not be stored in airtight containers as some air circulation is necessary.
SPRING PLANTING OF DAHLIASUpon examination in the spring you should find greater than 90% of your plastic wrapped tubers to be very firm and free of any spoilage. When it is time to plant or pot your tubers you can open the package, remove the tubers and check for “eyes” (where new growth will occur). Blind tubers, those without eyes, seldom produce new growth.Plant your dahlias in the spring after the last possible frost.
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FAQs
Place a dahlia tuber at one end and roll the plastic wrap around it a few times. Once the first tuber is enclosed in plastic, you can add additional tubers of the same variety, one at a time, rolling as you go. Each tuber should be fully enclosed in plastic and separated from the next tuber by a layer of plastic.
How do you store dahlias in plastic wrap? ›
Be certain that no tuber is touching another; plastic wrap must separate all tubers. You may wrap up to five tubers or so per package, but in the last 5-7 inches, fold over the side portions of the plastic wrap and continue to roll to completion.
Can I 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.
What is the best material to store dahlias in? ›
Typically, the tubers are then stored in a damp, clean material (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.
How to store dahlias over winter? ›
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 plastic bins? ›
If you're keeping them whole, then storing them in a larger tote or even a plastic bag, covered in peat (or whatever you're using) would work fine! Then if you notice too much moisture, you can just crack the bag open to allow some air movement. Generally, a basem*nt is a great place to store your tubers.
Can I store dahlia tubers in shredded paper? ›
Shredded paper works to reduce evaporation and drying out of tubers. Cardboard boxes or paper bags can be used, and peat moss, coarse sand, sawdust, wood shavings or vermiculite work instead of shredded paper. There's a balance on keeping the tubers dry without drying them out.
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 medium for dahlia storage? ›
Most growers seem to use vermiculite in plastic bags to store tubers that have dried for one to two days. Coarse vermiculite works better than the fine horticultural vermiculite.
Can you use straw to store dahlias? ›
Mulch the tubers with straw, compost or another organic material, and remove the mulch in spring, so the ground can warm up again. You may need to dig up and divide your dahlias at that time; large underground clumps will eventually yield weaker stems and smaller blooms.
If left in the ground, the tubers may rot and freeze in the winter. Even though I think it's easier to find viable tubers in the spring, you can also divide the dahlia roots before storing them for the winter.
What temperature is too cold for dahlias? ›
If they are outside or in a garage, a temperature below 35 degrees can kill them.
What temperature should dahlias be stored at for storage? ›
Temperature and humidity levels are the two keys to successful dahlia tuber storage. Your dahlias will need to be kept in a cool —but not freezing— environment, and they'll need relatively high humidity. We find that 38-50 degrees F (4-10 degrees C) is best, and you'll want to aim for 75%-85% relative humidity.
Can I store dahlias in plastic bags? ›
If they get too warm, they could rot. Humidity at about 80-90%. Ensure that the tubers are not too dry (they will shrivel) and not too wet (they will rot). If your space is dry, you can control this by storing in plastic bins/bags and occasionally spritzing with water.
Can dahlias be stored in plastic containers? ›
You can use any kind of container, crate, bins, boxes or bags. We use plastic storage totes with holes drilled in them because in our climate we are usually more concerned with tubers drying out. If you have perfect storage conditions, some people just store whole clumps loose in crates lined with paper.
Can I store dahlia tubers in a plastic container? ›
Tubers should not be stored in airtight containers as some air circulation is necessary. SPRING PLANTING OF DAHLIAS Upon examination in the spring you should find greater than 90% of your plastic wrapped tubers to be very firm and free of any spoilage.
Do you have to wash dahlias before storing? ›
After you've dug your dahlia tubers up (more information on how to do that HERE), we recommend that you do NOT wash or hose off your clumps of tubers. Some growers and gardeners do wash their tubers before storing them away for the winter, and we know that different things work for different people.
