Planting and care of dahlias

Planting and care of dahlias

Flower bulbs |

Dahlias are a colourful addition to every garden. Dahlias owe their great popularity to their many colours, varieties and shapes. Dahlias bloom lavishly from summer to the first frost. To make the most of your dahlias, here are some useful planning and care tips!

Summer-flowering flower bulb

Dahlia's are one of the summer-flowering flower bulbs, despite the fact that dahlias grow from a tuber. Plant the tuber in spring, from March to May. Dahlias can't handle frost at all, so be sure that you plant them after the last frost. If necessary, protect them by first planting them indoors in a pot. Or wait until your garden is no longer frozen. With the right care, you can enjoy the beautiful spherical flowers throughout the summer. Flowering runs from July to sometimes deep into November.

Planting tips

Dahlias can't handle frost, so wait until the end of April/early May to plant the tubers outside in open ground. You can also choose to wait, or start them indoors earlier. Grow dahlias in a pot indoors from the beginning of March. This is called forcing.

Plant the tubers in the pot with the roots pointing downwards and the stem upwards. Always use a deep flower pot so the roots have enough space to grow. Fill the pot with fresh potting soil, preferably potting soil for flower bulbs, and press the soil down lightly. Put the pots in a bright place with a temperature of at least 17 ºC and keep the soil slightly moist.

The dahlias can be moved outdoors after the last frost. You can choose to put the flower pot outside or you can replant the tubers in the open ground. Immerse the dahlia tubers in a container of water before planting them in the open ground. Leave them in the water for half a day. Plant the dahlias at least 3 cm deep in a hole that is wide enough for all the roots. Place the Dahlia in a sunny spot, in fertile, well-drained soil.

Care tips

Dahlias need a little more care compared to other summer bulbs. It starts before planting. Make sure that they get a spot in the sun and the soil is fertile. If it isn't fertile, mix some organic fertiliser into the soil. After planting the tuber, keep the soil moist. In addition, the Dahlia needs additional nutrition in the form of fertiliser. A tulip bulb, for example, doesn't need this nutrition. Nutrition gives the dahlias extra energy to grow and make new shoots. New shoots are very popular with slugs, so protect them properly with traps or plant enhancers.

The following tips can help enhance your dahlia's beauty and extend flowering:

  • Clip off the top of the plant once the plant has three or four leaves. This way the plant will be bushier.
  • Provide extra support, such as a stick, for dahlias higher than 80 cm.
  • For larger flowers, use your fingers to pinch off the side buds.
  • Remove off the side shoots that grow directly under the top bud. When the top flower is spent, new shoots will form along the stem to produce flowers.
  • Remove the spent flowers from the stems. Dahlias will then continue to flower far into autumn.
  • Make sure that they have plenty of ventilation. This protects the plant from mould.

Storing dahlias

Dig up the dahlia tubers in autumn after they bloom. Shake off as much soil as possible or rinse them with water. Take care not to leave any water on the tubers. The tubers are hollow so if water remains in them, they are likely to rot. To allow the moisture to drain out of the tubers, store the tubers upside down in a cool, dry place for a few weeks. Then the tubers should be kept in a crate. Cover them with sawdust or dry sand. In the spring, the dahlia tubers can bloom again and be propagated. From the end of summer to the end of autumn, you can enjoy your own beautiful dahlias!

Dahlias as a cut flower

As soon as the dahlia starts budding, it is best to regularly remove the side shoots between the top two or three top leaves. Remove both the leaves and the flower bud. The beautiful flowers on longer stems that result from this are also perfect as cut flowers in a vase. If you want to use the dahlia as a cut flower, put the stems in boiling water for a few seconds. You can also cauterise them over a flame. The beautiful flowers of the dahlia will stay fresh even longer!

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