How To Overwinter Dahlia Tubers

01/21/25

10 minutes Read

Written By Johnsons Team

Known for creating dazzling displays throughout the summer and autumn months, dahlias are a favourite amongst colour lovers across the nation. During the winter, however, dahlias can’t promise the same vibrance they did in the previous seasons. This is because they are not frost-hardy - meaning they can’t survive the cold temperatures that come with the winter months. There are steps, however, that you can take to ‘overwinter’ your dahlia plants and ensure that they can be replanted the following spring for even more healthy blooms.

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What Is Overwintering?

Before discovering how to overwinter dahlia tubers, let us explain exactly what overwintering is. Overwintering is a means of protecting your plants from frost to keep them alive until they can be replanted in spring or summer. It can involve removing your tubers from the soil and storing them in a warm location until the final frosts the following year or, in warmer conditions, covering them with a protective layer of mulch.

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What Are the Benefits of Overwintering?

Gardeners may overwinter their plants for a variety of reasons. Impassioned gardeners with a sentimental tie to their flower plants may overwinter their tubers to preserve specific plants that mean something special to them.

Overwintering is also economical. By protecting your tubers during winter, you can avoid buying brand-new ones the following year. Not only is this cost-effective, but it also gives your plants a headstart in the following growing season, as your tubers already have large and established root systems.

How to Overwinter Dahlia Tubers

We tend to recommend lifting your dahlia tubers for overwintering in colder areas as tubers won’t survive a thick frost or extended periods of cold, wet weather.

Once the first frost has blackened the foliage, lift each plant with a fork, taking care not to spear the tubers and brush the soil away from the roots. Dispose of any tubers that are showing signs of rot or damage, as this could spread in storage. Cut back the stems and place the tubers upside down, allowing any moisture to drain away freely and naturally. Once dry, wrap them in newspaper or pack them in dry straw or compost and place them somewhere dry and frost-free, out of direct sunlight.

In warmer parts of the country or areas that are particularly sheltered and whose soil is well-drained, it may be possible to leave tubers in the ground. A good layer of mulch, well-rotted manure, straw, or garden compost will help to protect tubers from light frosts.

Shop Dahlias at Johnsons

Now that you know how to overwinter dahlia tubers, grow premium blooms with Johnsons and protect your cut flower garden from frosts. With over 200 years of experience, Johnsons is a trusted provider of all things dahlias. So shop your gardening essentials here and prepare to bring colour and life to your outside space.