Dahlias are beautiful garden plants. They do best in the bed, but there are some varieties that also unfold their splendor in the bucket. Dahlias are originally from Mexico. The beauty of these flowering wonders is their variety of colors and variety of flower shapes. A distinction is made between single-flowering dahlias with an open centre, ruff dahlias, water lily dahlias, deer antler dahlias and many more. The multi-variant perpetual bloomer is an integral part of the garden between July and October. Dahlias go very well with grasses such as perennials, riding grass or moor grass, with summer flowers such as snapdragons, zinnia, mussel flowers or summer asters and with perennials such as daylilies, phlox or coneflowers.

Caring for Dahlias

Caring for dahlias is not complicated. It is important that the plants are supported. When they fall apart, their beauty is quickly gone. That’s why dahlias should not be left to their own devices! Support is not important for all strains, only for those that grow to over 80cm tall and those that produce large and heavy buds. If you want to achieve larger flowers, you have to break out all the side buds. If you have the right location and a good substrate for the plants, you don’t have to do much. Dahlias don’t need much water, fertilizer only at the beginning, so there isn’t much to do besides planting and digging. It is important to protect the young dahlias from slugs, because these beasts like the beautiful flowering plants.


The ideal location prevents diseases, especially fungal diseases. You should therefore choose the right place with care!

  • Sunny location
  • Long stems and weak flowers develop in the shade.
  • A sheltered spot is ideal
  • Do not plant in front of a heat-radiating wall or wall!

plant substrate

Dahlias do not place excessive demands on the plant substrate. It must not be very loamy and not prone to waterlogging. Otherwise the plants are uncomplicated.

  • Loose and slightly moist soil
  • Absolutely water-permeable subsoil
  • Nutritious soil is favourable
  • In soils that tend to waterlogging, the dahlia grows weakly and can even die off due to rot.
  • Dahlias do not like loamy soil.


Since dahlia tubers are not hardy, they have to be taken out of the ground every autumn and, of course, planted back into the ground the following year. This isn’t complicated, it just takes a little work, depending on the amount. If you do everything right when planting, you will have a lot of fun with your magnificent flowers.

  • The ideal planting time is mid to late April, when night frosts no longer penetrate deep into the soil.
  • If stronger frosts threaten again, the freshly sprouted dahlias must be covered!
  • It is best to soak tubers in water for 24 hours before planting!
  • Tubers that have grown too large can now be divided. Use a sharp knife to cut the tuber into several parts, each with at least one shoot.
  • Insert about a hand’s breadth deep!
  • When planting in spring, provide good compost, horn and bone meal and horn shavings
  • Depending on the variety and height, it is ideal to place three to four support sticks next to the tuber when planting. It should be re-tied every two to three weeks. This prevents the plants from falling apart.

Dahlias in planters

Many dahlias are suitable for pot culture. You should rather choose smaller varieties, there are great flowers there too. The tub dahlias are planted at the same time as the outdoor ones.

  • The diameter of the planter should be about half the height of the plant!
  • Plant tubers about 10 cm deep!
  • The distance between the tubers in the pot is about half the growth height.
  • If the tubers are planted too close together, the foliage will become very narrow and dry poorly when wet. This can lead to fungal diseases.
  • Sunny location!
  • Dahlias in containers require more water than those in the bed.
  • Do not water too much and excess water must be able to drain away.
  • Fertilize when planting and supply flowering plant fertilizer regularly!

watering and fertilizing

Dahlias don’t really need a lot of water. They handle drought quite well and show when watering is needed. However, one should not always wait for the leaves to hang limp, as this will damage the plant in the long run. But every now and then it’s not a problem. Permanent wetness, on the other hand, is not tolerated.

  • Only water if the drought persists!
  • Always water from below, never on the leaves (fungal diseases)
  • Do not water too much to avoid excessive growth of green parts of the plant!
  • Only fertilize when planting, otherwise the dahlias will become too bulky, susceptible to fungal diseases and also weak on their feet.
  • If the soil is very sandy, it can be fertilized again, because a lot of fertilizer is lost through leaching.
  • Under no circumstances use mineral fertilizers, which ensure rapid growth, but lack the power.

To cut

In order for dahlias to bloom until frost, dead flowers must be removed regularly! Otherwise you only have to cut at the end, namely completely down, about hand high above the ground.

  • The more stems with flowers are cut (vase), the more the dahlias will bloom.
  • One cuts faded flowers above the next bud, so that new blossoms form again and again.
  • No more pruning is required unless disease is developing and diseased foliage needs to be removed!


Dahlias are sensitive to frost. The tubers would not survive the winter in the garden soil. That’s why you dig them up. The best time to do this is when the first cold night has made the foliage of the plants soggy. You can see that very well. When the leaves are gone, it’s time to take the dahlias out of the ground.

  • Cut stems back to 20 cm!
  • Carefully remove the tubers from the ground with the digging fork!
  • Let the tubers and soil dry in a sheltered place!
  • Then put everything together, sorted by variety, in large flower pots or in crates and set them up in a frost-free, but cool place!
  • Temperatures between 4 and 10 °C are ideal.
  • Balanced humidity is important. It must not be too high. Then it is better to store the tubers in boxes with sand.

Multiply – instructions

Dahlias are propagated by seed, division or cuttings. It’s not complicated, but needs to be done properly. The problem is the varietal propagation. If you want an identical plant, there are three ways: propagation by cuttings, tuber division and cell propagation. The latter is only for professionals and is done in the laboratory. When you sow, you always get new varieties.

  • Propagation by division – make sure to divide before planting!
  • There must be at least one bud on each tuber!
  • Propagation by sowing – bring them forward in March and they will germinate after just 10 days, flowering in the year they were planted
  • Cuttings – cut from the tuber, the best time is January, beginning of February, if possible in the greenhouse, in any case without drafts.
  • Place the tuber in a box, cover lightly with soil, keep moist, at least 15 degrees and leave the neck of the stem free!
  • Fresh shoots can be plucked from a length of 3 cm. Dab with root fix and put in a box with standard soil!
  • Cover the cuttings with foil or a bag! Water and air regularly! Absolutely avoid drafts!

diseases and pests

Diseases can be prevented by a good choice of location, good soil loosening and sufficient planting distance. In addition, the leaves must not be watered!

  • Snails – sprinkle slug pellets as soon as they emerge, use products such as Ferramol, which do not harm angels or other animals! Snail fences are very useful, but expensive for large beds!
  • Spider mites and aphids – rinse off or use appropriate means!
  • Voles – Plant dahlias in baskets made of plastic-coated chicken wire or in plastic pots with many holes drilled in them
  • Mildew – in damp locations and wet weather, spray fungicides
  • Leaf spot disease – in moist locations and wet weather, it first shows up on older leaves. Dispose of leaves, neither on the plant nor just lying around! Use fungicides!

Particularly beautiful varieties

It is a matter of taste which dahlias you like best. Here is a small selection:

  • ‘Kaiser Wilhelm’ – ball dahlia with approx. 10 cm large yellow-pink flowers, oldest German variety still available
  • ‘Verdi’ – 60cm tall, dark red petals with large white tips unfold from a green centre
  • ‘Alpen Diamond’ – Ruff Dahlia, pastel pink flower
  • ‘Summertime’ – single bright lemon yellow flowers set against dark red foliage
  • ‘Night Butterfly’ – Ruffed Dahlia with mysterious dark red, velvety flowers with a light ruffle
  • ‘Caribbean Fantasy’ – semi-cactus dahlia with great flower markings in dark red and white
  • ‘Clair Obscure’ – Dekasplit flower, new flower shape, beautiful dark pink color with white tips
  • ‘Fraureuth’ – Semi-cactus Dahlia with 14cm flowers in salmon pink
  • ‘Alexander Voit’ – Semi-cactus Dahlia with flowers up to 20cm in deep pink with a yellow base
  • ‘HGWinkler’ – Semi-cactus Dahlia with orange-yellow flowers up to 18cm
Tip: A very good source for dahlias is Heinz Voit, a retired master gardener and award-winning dahlia breeder from Fraureuth near Zwickau in Saxony. A list of offers can be requested by phone. Unfortunately there is no website. It is purely a hobby breeding.

Dahlias are great flowers. Until a few years ago, they were still considered old-fashioned and were best suited for cottage gardens. There are now such great flowers that no one can call them old-fashioned anymore. With so many varieties (about 10,000) it is difficult to choose just a few specimens. If you don’t have a problem with snails, you have to have dahlias in your garden. The great plants can be combined very well and you can do it differently every year. With which other flowers do you have this opportunity, every year a new bed. I love dahlias, not all of them, but lots of them, and researching and writing made me really want to get a few more.

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