Dahlias just look delicate, those stunning blooms look like they could disappear at a moment’s notice. But is this true? Are dahlias able to grow as perennials in the UK or are they just too soft for our winters?
Are Dahlias Perennial In The UK?
So, the short answer is yes, they are perennial in the UK. But only with a Gardner looking after them, they would not survive as perennials in the wild in our climate.
In hotter places of the world, they happily grow as a perennial without as much care, but they are cut out for our British winters.
All of the foliage will die back over winter but it is the root of the plant that survives with lots of stored energy. The plants then burst back to life in spring using the energy stored up in their root system.
How To Protect Dahlias Over Winter
When it comes to helping these tender plants survive winter it all comes down to what you do with the roots.
There are two main options open to you as the gardener, dig them up and store them before replanting in spring, or leaving them in the ground but with added protection, let me talk about both.
Lifting and Storing Dahlias
If you are going to dig your Dahlia tubers up and store them over winter then follow my quick guide below to ensure you give them the best chance possible.
To begin with, you will want to cut the foliage back almost to the base of the plant.
Once this is done gently lift them using a garden fork. You want to dig well away from the plant, to begin with, to make sure you don’t accidentally stick your fork through the tuber.
Remove any soil from the tuber by giving it a good shake and also a quick brush with your hands. I then like to leave the tubers in the sun for a few hours to dry out.
If the weather is poor then move them into a greenhouse or put them on a windowsill for a while to dry.
You then want to hang them upside down for a couple of weeks to make sure they are really dried out. Now, this obviously needs to be done in a frost-free place as the tubers are really vulnerable at this point.
If an early frost is forecast then you may want to consider bringing them inside.
After a couple of weeks of hanging, they will be ready for their winter hibernation. Wrap them in one or two sheets of newspaper before storing them over winter. You want a frost-free spot but one that also has decent ventilation.
A garage shed or greenhouse is usually a good idea. (depending on the weather greenhouses can get a little chilly so this really depends on your location and the weather that winter)
Leaving Dahlias In The Ground
If you have a smaller garden and no greenhouse or garage in which to store your Dahlias then it may be better for you to leave them in the ground.
This is also true for gardeners who want to enjoy Dahlias but just don’t have the time to dedicate to digging them all up and planting them all over again next year.
To start with you want to remove all vegetation from the plant right back to the base. Use some good secateurs for this as Dahlias can have tough almost woody stems.
You then want to apply a really thick mulch on top of your Dahlias, this is the secret to protecting them over winter.
You can use compost, leaf mould, bark, anything really as a mulch just make sure it is really thick. This should help prevent the ground underneath from freezing which will, in turn, protect your dahlias.