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Mouldy dahlia tubers?

If you lifted your dahlia tubers this year, there's a high chance that they will be mouldy and here's why.

The challenge that lots of gardeners experienced in 2022 was that the weather was very mild until the middle of November and we all enjoyed picking our lovely dahlia flowers for longer. However, when it came to lifting the dahlia tubers, there had been lots of rain and they went into storage still damp.

When you combine this with the sudden drop in temperatures to -5 over an extended period, the dahlia tubers didn’t stand a chance and its no wonder that so many of you got in touch to tell us that your dahlia tubers had gone mouldy.

Dahlia tubers are made up of a high proportion of water which means that if they freeze, they will turn to mush when they thaw out and then start to go mouldy. No one likes a mouldy dahlia tuber!

They are tender perennials which means that if you do decide to lift them over the winter, they must be dry and stored somewhere frost free until they can be planted again in April/May.

Mother Nature is a tough teacher but there are a couple of things that you can do differently for this season:

1. Leave the dahlia tubers in the ground

If you live somewhere that is relatively protected and you have good, free draining soil, you can leave your dahlias in the ground over the winter and make sure that you

cover them with a very thick layer of mulch. This can be in the form of compost or organic matter such as leaves, wood chip or even cardboard but it must be thick enough to prevent the frost getting to the tubers.

*There is a risk that they might get frosted and you might not know until the spring by which time its too late to order more!

2. Dig the dahlia tubers up early

If you want to ensure that your dahlia tubers dry out effectively before you put them into storage for the winter, you could lift them at the end of October. By lifting them before the weather turns extremely cold, you’ll stand a good chance of them drying properly in a shed or greenhouse before putting them into storage.

3. Dry them indoors before storing

If we have a long flowering season like last year, you could lift them in mid November and bring them into the house to dry out. Just leave them for a week or so on a sunny windowsill or next to a radiator to ensure they are fully dry before putting them into a box with straw or wood shavings to store.

4. Treat them as annuals and buy new

If you cannot be bothered with mulching or storing, the other option is to just treat them as an annual. If you consider that in the right growing conditions, each dahlia tuber will give you on average 20 flowers over the course of the season and each flower would sell for £2, the dahlia tuber has done it’s job and its a great opportunity to try new varieties.

(Variety - Cornel Bronze)

Our dahlia tubers are kept at the perfect condition until they are sent out to our wonderful customers from the beginning of March. We always recommend buying dahlia tubers online rather than from a heated garden centre or shop as these will have been displayed in store since January and will, over time, dry out and compromise the quality for the tuber.

Why not check out our wonderful Dahlia Beach Collections which come with 5 perfectly curated dahlia tubers and 3 packets of flower seeds to create a huge display in your garden for this summer. We're going to be doing lots of video on our private Dahlia Beach Facebook Community on how to take cuttings from our tubers this spring which will at least triple your stock!

Who's looking forward to getting started this season? I know that I am!

Andie x

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