Overwintering dahlias: expert tips

Flowering dahlias make your garden shine in the summer. But in order for them to form flowers for several years, they must be skilfully brought through the winter.

Dahlias (Dahlia) are among the low-maintenance plants in the garden in summer and quite reliably form many of their brilliant flowers. However, proper handling of the subtropical plant in our latitudes includes the annual wintering of the dahlia. But do dahlias have to be overwintered everywhere, and how do you protect the plants properly from the cold? We explore these questions below.

Are dahlias hardy?

Dahlias originated in Mexico and came to Europe only in the 18th century with sailors. Therefore, due to their warm origin, they are very sensitive to frost and should not spend the winter outdoors. In mild regions of Europe, such as the wine-growing climates, an attempt can be made to leave the tubers in the ground even in winter. However, in this case, make sure that you have a decent cover layer of brushwood, leaves and straw. Even there, overwintering is associated with a high risk and digging up the tubers is still the most sensible method.

Overwintering dahlias: digging up and storage

The best time to dig up the dahlia tubers is in autumn, immediately after the first night frost. To do this, the first step should be to cut down the remaining greenery of the dahlia to a height of 10 cm above the ground, and only then dig up the tubers. Be very careful when digging, so as not to unnecessarily injure the roots. Ideally, get the tubers out of the ground on a dry day to make it easier to remove the soil from the storage organs. For storage, a cool and dark place with good ventilation is always recommended, but it must also be frost-free. Lay out the tubers on paper or sand so that they do not touch each other directly. Stored in this way, you can put your tubers in the ground again the following spring.

Heed the following points when overwintering dahlia tubers:

• Dig on a dry autumn day
• Cut the plant down to 10 cm
• Store in a cool, dark and airy place
• Lay out on paper or sand

Successfully overwintering dahlias in pots

For dahlias that you cultivate in pots, it is quite sufficient to place them in a frost-free and cool place in autumn. Additional digging is not necessary in this case. Nevertheless, cut the plant about 10 cm above the ground, as in the case of wintering dug-up tubers. The dahlia will sprout again at this point the following year.