Store your tubers for the winter
The dahlia is a beautiful flower, but keeping it can sometimes cause headaches. If this is the first time you are growing dahlias, be aware that you must remove the tubers from the ground in the fall since they cannot stand frost. If you don't want to bother with that, you can always dig them up and bake yourself a great dahlia cake.
If you want to multiply your tubers, here are some tips to help you with winter storage.
First of all, you have to identify your tubers before storing since they all look the same in the end. We identify them using a permanent marker directly on the tuber, so we are sure not to mix them up. If you have several tubers of the same variety, you can only identify the container or place an identification stick inside.
Controlling temperature and humidity
The ideal temperature for storing tubers is between 4°C and 10°C (40-50°F). What is more difficult to maintain is the humidity of the room: it must not be too humid to cause mold nor too dry so as not to dry out the tubers. If you have a garage that you heat to a minimum or a cold room, it is practically ideal if not the coolest place in the house. Unheated garages and sheds should be avoided because of the risk of freezing.
Container for storage
Virtually any container can be used for storage: a cardboard box, a wooden box or plastic bins. If you use the plastic bins, be sure to drill a few holes in the lid to allow air to circulate.
What should I store my tubers with?
You will need to use different materials to "insulate" your tubers while keeping some air circulation so that they remain intact.
Horticultural vermiculite (coarse-grained) can absorb excess moisture without drying out the tuber and allows air circulation in the container. This product is expensive and it is best to wear a mask when handling it. Construction vermiculite should be avoided since small grains and dust can rot your tubers.
Peat moss (also called Peat Moss) gives good results and is not too expensive. On the other hand, it is necessary to pay attention to its humidity level. It may be too wet if the bag has been punctured. If this is the case, do not hesitate to mix it with a dry product (wood shavings for example) to balance the humidity. On the other hand, if the product is too dry, it can dry out your tubers. So you can spray a nice amount of water on the peat moss.
The wood chip
Wood shavings (wood shavings) are the least expensive product. Just like peat moss, you have to be careful with the moisture content if the bag has been punctured. It is also necessary to check that there is not too much sawdust (dust) in the container since this limits the circulation of air and increases the risk of rot. Wood can also absorb excess moisture and allow good air circulation. You can find this product in pet stores that use it as litter or a COOP, a feed mill, horse breeder, etc. Choose the biggest ripe.
Sand can be a product to use.On the other hand, it is heavy to handle and can promote rapid germination in the spring
After choosing your product, you can insulate the bottom of the box with a good layer and place your tubers without them touching each other. If the box allows, lay a new layer of insulation and a new row of tubercles. When your container is full, carefully cover your tubers.
Plastic wrap technique
Personally, we don't use this technique since we would have to buy way too much plastic wrap. However, we know of several other dahlia growers who have had great success with this technique. It's a good alternative if you don't have a lot of tubers.
First, roll a first tuber in the plastic wrap 2 or 3 turns to insulate it well. Place another tuber on top of the first and roll a few more turns. Repeat this sequence with the rest of your tubers. Depending on the size of the tubers, you can make bundles of 10 without any problem. When your package is finished, fold the sides over the package to keep in the humidity.
The miracle recipe
Unfortunately, there is not one way to do it for everyone. Several factors will affect the conservation of tubers: storage location, temperature, humidity, etc. What we recommend is to go and have a look once a month to make sure the tubers are doing well. You will quickly see if it is too hot or if it is too humid. If a tuber is moldy, discard it immediately so as not to mold others in the container.
Keep in mind that we do not keep all of our dahlias. Even if we have a well-tempered cold room, we also sometimes lose tubers during storage.