How to grow beautiful Dahlias in pots

From the planting up to overwintering, find here all the right advice on how to obtain abundant blossoms. Dahlias are unmatched!

Planting: you cannot get easier
The right time to plant Dahlias is when Lilacs start blossoming, that is to say at the beginning of April (in the south) up to the end of April (in the north). The tubers must be 2cm underneath the soil's surface. Dahlias like a rich soil but hate any adding in of compost or manure. A little bit of potting compost does not do them any harm in heavy soil but this is all they need. Keep an eye for slugs 'attacks as they love them and for the rest, just let them settling in!

Dead-heading means twice as much flower
The blooming of Dahlias starts during summer and carries on until the first autumnal frosts, which can arrive fairly late. During this time, you must look after your Dahlias as they must last a long time! The main care is to dead-head the withered flowers. It is a simple gesture but it will allow you to get twice as much flowers. Therefore cut the heads as soon as they wither.

Staking and fertilizing
Think about supporting the stem which is not very solid. On a terrace or a balcony, gusts of wind can be fairly strong, even in summer. Bury a stake near the stems as soon as they reach 40cm in height or when they form the first flowering buds. This will avoid the flowers lying down in case of stormy weather. Make the most of this to give your plants a fertilizer at their base, approximately every three weeks. A vegetables' fertilizer is suitable for Dahlias but you can also supply them with roses' fertilizer.

Good to know
Dahlias tend to form less double flowers at the end of the season. It is simply because the roots are hungry and they form more flowers than before. Increase the frequency of fertilizer's supply.

Overwintering
Dahlias are not hardy, in other words they must be sheltered from frost in winter. But do not worry, it is simple. As soon as the first frosts have blackened the foliage, cut the stems about 5cm above the ground. Lift up the tubers gently and discard surplus soil. Place them in some sand, peat, light soil or even in woods' ashes, burying them by three- quarters. Store them in a basement or in a cool, frost-free room, with, ideally temperatures of between 12 to 15° C until next April. You can also cut the stems right back and simply place the pot in the basement. In both cases you will be able to grow your Dahlias for years and years!