Dahlias…to lift…or…not to lift?

However much survives the storm we are all asking the same question….what to do with our Dahlias?

Dahlias, should you lift them or leave them in the ground?
Dahlias, should you lift them or leave them in the ground?


Dahlias are tender tubers, very similar to Potatoes, if you freeze a potato, due to the high water content, they will turn to mush when they defrost…eek!

Keeping your dahlias on the dry side gives them a much better chance of pulling through the winter.

The best defense is excellent drainage…, here at Swan Cottage Flowers, we garden on a light sandy loam, which proves a challenge keeping everything fed and watered during the growing season…but is excellent for overwintering Dahlias.

If your soil is heavy then a layer of horticultural grit under the tuber, this will help with drainage and prevent the tuber sitting in water, getting waterlogged, then freezing or rotting.Dahlias, make sure you label your plants! Like Tulips, they all look the same when they are sleeping!

If you garden on heavy clay soil and you have not put in any of these precautions, then I would advise lifting your tubers…

When lifting we have found moving each tuber to it’s own pot of dry compost has been significantly more successful than any other method…its isolated from pest or diseases and the compost provides the best protection against temperature fluctuations, once the weather warms up, simply water!

Don’t forget to label your plants, when they are sleeping they all look the same and you quickly forget which dahlia is which!

Here in the South of England our winters tend to be mild and our part of Buckinghamshire lies in a very dry region nestled behind the Chiltern Hills, so we will leave most of our tubers in the ground to overwinter.



We will let or Dahlias continue to grow until the frost eventually knocks them down!Overwintering Dahlias at Swan Cottage Flowers

This ensure that the dahlia tubers have had the very best chance to store up enough energy to come back bigger and better next season (and potentially provide excellent cutting material for new plants).

If you would like to overwinter your plants in the ground then we recommend protecting them from excess wet conditions…

We will replace our grow frames, adding polythene lids (follow us on Instagram) to keep the Dahlia Tubers dry and the ground temperature just a little warmer.

If you have just one or two plants you can use cloche to do the same job or for an allotment as row cover (fleece or plastic low tunnel).

For a bigger area, you can keep your plants protected by adding layers of mulch, compost straw or plastic to keep the soil dry and stop the frost from penetrating the ground too deeply.

All of these methods can create a slug / snail hotel so do put down some protection  and this will ensure you always start to control the slug / snail population well before they become a nuisance – prevention is always the best defense!

Once spring is sprung, inspect the tubers and clear away any debris.

Dahlias emerging after the winter, don't forget to use slug protection!
Dahlias emerging after the winter, don’t forget to use slug protection!

The really awful winter of a few years ago killed everything no matter how you stored your precious plants, so always insure yourself by investing in a few new tubers or cuttings each season.

Go on…try something new!


Zoe x

Zoe Woodward, Swan Cottage Flowers


Swan Cottage Flowers, WorkshopsWedding Flowers

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2 Comments Add yours

  1. Nic Hamilton says:

    Always interesting to see the other side and I’m very impressed by your protecting structures. We leave our garden ones in situ but lift those grown for cutting (750 this year so not looking forward to it!). As well as horrible heavy clay we lift because we start mainly from new cuttings every year. Come on first frost, I want to start digging! 😉

    An excellent piece, thanks for sharing.

    1. Thank you so much for your kind comments

      The grow frames saved our bacon this season, so much so I’ve ordered some more from the Husband!

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