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You have ordered dahlias, the tubers have already arrived, and the weather outside clearly has no intention of cooperating.
That does not mean you have to leave them in their packaging and wait anxiously. You can temporarily pot them up and keep them in a protected place until temperatures are suitable for planting outside.
The process is simple. The important thing is not to let the tubers dry out, but also not to keep them sitting in constantly wet soil.
What I Do With Dahlia Tubers While the Weather Is Still Cold
Dahlias usually arrive with some growing medium around the roots to protect them from excessive drying during storage and transport.
The tuber clumps can look very different - some are large and branched, while others are more compact. And yes, sometimes they do not look particularly promising.
There is far more life in those tubers than their appearance might suggest.
If the tubers are slightly dehydrated, in my own experience I have soaked them in water overnight before planting.
Step 1: Prepare the Pot
I choose a pot according to the size of the tuber clump. It does not have to be the final container - the aim is simply to give the tuber a safe temporary home until it can be moved outside.
I add some drainage material to the bottom, followed by a little soil.
Step 2: The Soil Should Be Slightly Moist
For temporary planting, I use a light universal potting mix. The soil should be slightly moist, but not wet.
If it is dry, I prefer to moisten it gradually with a spray bottle rather than soaking it immediately with a large amount of water.
At this stage, the tuber does not yet have developed foliage using much water. Excess moisture around it is a greater problem than a slightly dry growing medium.
Step 3: Place the Whole Tuber Clump in the Pot
The easiest way is to place the entire tuber clump on top of the prepared soil, with the stem and the area containing the buds facing upward.
If shoots have already started to emerge, I work particularly carefully because the young growth can break very easily.
Step 4: Cover With Soil
Once the tuber clump is in position, I cover it with a small amount of soil.
I do not press down firmly. The aim is for the growing medium to fill the spaces around the tubers without compressing them.
A gentle shake of the pot is enough to help the soil settle into place.
Step 5: Don't Forget the Label
Finally, I add the variety label.
This seems like a tiny detail until May arrives and you find yourself with six identical pots, absolutely certain that you will “definitely remember which one is which.”
How Long Can a Dahlia Stay Like This?
A temporarily potted tuber can remain in the container for around a month while you wait for outdoor conditions to become suitable.
I keep the pot in a protected place where the temperature remains above freezing.
I do not allow the soil to dry out completely, but I also do not keep it constantly wet. If necessary, I lightly mist it.
When Can the Dahlia Be Planted Outside?
I wait until temperatures have risen consistently and the danger of temperatures dropping below freezing has passed.
The whole plant can then be carefully moved to its permanent position in the garden.
There is no need to disturb the root ball more than necessary. The purpose of temporary potting is to help the dahlia pass through this period safely and then move it with as little stress as possible.
What If the Dahlia Will Stay in a Pot Permanently?
The procedure is almost the same, but in that case I choose a larger container and make sure the soil is richer in organic matter and compost.
During the first few weeks, while the first leaves are emerging and the plant is beginning active growth, I continue to be careful with watering.
Too much water during this early stage increases the risk of the tubers rotting.
The aim is not to make the dahlia grow as quickly as possible. The aim is to get it safely through the cold period until the weather outside is finally right for it.