Dahlias are undoubtedly one of the most established garden flowers in our latitudes - their usually spherical, lush flowers are simply part of a classic flower garden. Here is an overview of cultivation rules worth knowing and the enormous variety of varieties of this genus.

The beautiful dahlia is one of the classic garden flowers

Table of Contents

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  1. origin
  2. blossom
  3. heyday
  4. Which location is suitable?
  5. plant out
  6. What is the best planting time?
  7. Dahlia in pot
  8. hibernate
  9. Fertilize the dahlia properly
  10. Prefer
  11. multiply dahlia
  12. divide
  13. Draw
  14. tip
  15. sorts

    16. origin

    For many, dahlias are part of the familiar image of their home regions. They have always had a permanent place in gardens of many generations and are currently experiencing a certain comeback. Originally, however, the genus comes from very distant countries - the Spaniards discovered it around 500 years ago in the high plateaus of Mexico and Guatemala and brought it to Europe from there. Even in their native areas, dahlias were traditionally valued as ornamental flowers by the Aztec natives.

    blossom

    The blossom of the dahlia is certainly the most important thing for the local ornamental garden culture. Spherical, double flowers are most commonly associated with dahlias - however, there are many different species within the dahlia genus, some of which also offer completely different flower appearances. In addition to the many lavishly filled flower types, there are also open, disc-shaped types such as single-flowered or star dahlias.

    The typical and probably also the most popular double varieties are particularly suitable for bed designs in combination with filigree ornamental grasses or for effective bouquets of cut flowers. Due to their heavy, dense abundance of petals, however, the double varieties tend to snap and may need to be supported by stakes or low hedges.

    Nowadays there are hardly any limits to the colors of the hobby gardener. The range of countless breeds leaves hardly a nuance - only deep blue or black varieties are not included.

    heyday

    The flowering time of dahlias varies slightly from variety to variety, but generally they fill the garden with their splendor during the usual peak flowering period over the summer months. Some varieties show their first flowers as early as June, others only in the course of July. They can persist into autumn until the first frosts.

    Which location is suitable?

    In the garden, dahlias prefer a sunny, warm location. They also like it warm on their feet. The soil should be rich in nutrients, deep, permeable and not too dry.

    plant out

    Because of their relatively high nutrient requirements, you should prepare a humus-rich substrate for dahlias. Work plenty of compost, horn shavings (€32.93) and also stable manure underground at the planned planting site. When planting the individual tubers, you should keep a distance of about 50 and 80 centimeters - depending on how big the variety is. Bring them into the ground at about twice the height of the tuber. For better germination, you can soak the tubers in water two days before planting.

    What is the best planting time?

    Dahlias are planted in late spring, after the last danger of frost has passed - i.e. after the ice saints. This applies to both annual and perennial varieties.

    Dahlia in pot

    If you don't have extensive beds available, you don't have to do without dahlias. They can also be cultivated in a pot on a terrace or balcony. This even has several advantages:

    • Early flowering: If you keep the dahlias in pots anyway, you can get them used to the upcoming light from early spring and get them to flower early at the end of May.
    • Mobility and easy wintering: you can place your dahlias in the pot anywhere on the terrace, on the balcony or in a seat in the garden. Provided the place is sunny, of course. A bucket with colorful dahlias is always a summery, enhancing decoration for the enjoyable stay in your own oasis. In addition, the hibernation procedure is of course made much easier - instead of having to laboriously dig up and store the tubers, you only have to put the dahlia pot inside when frost sets in.
    • Less risk of rot and snails: In the bed, dahlias tend to rot in very wet weather. With a fixed planting place in the bed, this is difficult to prevent. On the other hand, if you keep your dahlias in a bucket, you can control their water supply yourself and only water them so much that they remain moderately moist. Snails are also easier to keep in check when growing in buckets. Standing on the terrace, the voracious pests tend to stay away from your dahlias anyway - you also have a better overview of the plants with a tuff in the bucket.

    The substrate in the tub should be nutrient-rich, just like in the bed. It should also have a lot of volume - so use the largest possible planter. You can also enrich the soil with compost and horn shavings (€32.93) for the long-term supply of the heavily consuming dahlias. In addition, they should be fertilized regularly - this is very easy to do in the bucket with a normal liquid fertilizer once a week.

    hibernate

    According to their habitat of origin, dahlias are not frost hardy. A separate hibernation is therefore necessary in our latitudes. In the bed culture, the tubers must be dug up and stored. In autumn, wait until the flowers have lost all their foliage and then use the digging fork to dig up the bulbs. Then first let them dry for a few days so that they do not rot when stored and then put them in a box filled with sand. Put them in a cool, dry place - for example in an unheated basement. The temperature should be around 5°C.

    To remember:

    • Allow dahlias to fully defoliate in fall
    • Then dig up the tubers and let them dry
    • Store in a box filled with sand and place in a cool place around 5°C

    Fertilize the dahlia properly

    In the bed, dahlias are best supplied with organic long-term fertilizer when planting, i.e. by mixing mature compost, stable manure and/or horn shavings into the soil. If you keep your dahlias indoors, you should provide them with a universal fertilizer every week during the growing season throughout the summer.

    Prefer

    Preparing dahlias can be worthwhile if you don't want to wait too long for them to flower in summer. They often flower much earlier with a pre-flowering phase in early spring. To do this, put the tubers in pots from the end of February and place them on the windowsill. From May 15th you can then put them outside in the bed and look forward to an early flowering splendor.

    multiply dahlia

    Dahlias are best propagated by cuttings or division. With the cuttings method you have the advantage of a higher yield. Each tuber has a capacity of about 10 to 20 shoots capable of being cut.

    In order to get cuttings, you have to advance the tubers early in the year, preferably at the end of January. To do this, place them in pots with potting soil and leave the shoot buds exposed. Keep the soil well moist and ensure an ambient temperature of around 15 to 20°C.

    When the tuber has formed shoots after 2 to 3 weeks, simply cut them off with a clean knife and put them in their own pots with potting soil and some rooting powder. It is best to cover the cuttings pots with foil so that they can thrive in a warm, evenly humid microclimate. Rooting takes about two weeks. After gradually getting used to the cooler temperatures and more irregular humidity, you can place the young dahlias in the bed as usual from the ice saints onwards.

    The cutting method at a glance:

    • Drive out the tuber from the end of January
    • To do this, place them in potting soil with the shoot buds open
    • Cut off shoots and put them back in pots with potting soil
    • Allow to root with evenly moistening and warm, bright conditions
    • Plant out from the end of May

    divide

    The much simpler but not quite as productive propagation method is dividing the tubers. To do this, cut a tuber in half before planting it out in May and make sure that each section has an eye that can sprout.

    Draw

    Finally, dahlias can also be grown from a seed. You can either buy seeds from specialist retailers or collect them from your own plants in the garden. However, you have to pay attention to the right time. After the flowers have faded, the seed coat will burst open on its own - a sign that the seeds it contains are now ready to germinate.

    Carefully collect the seeds and store them over the winter. You can then sow from March in a room with a temperature of 18 to 20°C in a bright window seat. Keep the slightly soil-covered seeds evenly moist in the seed trays, possibly under foil. After about 10 days they should germinate. From April you can separate them and plant them outside in May after the ice saints.

    Mind you, when you grow seeds, you don't get a clone of the mother plant. It is therefore possible that other flower colors result from the daughter plants. But it is precisely this surprise effect that is particularly appealing to many hobby gardeners and almost a challenge for breeding experiments.

    tip

    If you want your dahlias to have a particularly rich bloom, you can pinch them about 10 days after planting them out. By cutting off the individual shoot tips, the plant is stimulated to branch further and thus to multiply the flowers. You should always cut off faded flowers immediately to encourage new flowering.

    sorts

    Dahlias are a very diverse genus. They are systematically divided into 4 sections and a total of about 35 species. For the local garden culture, however, only the Dahlia section is actually relevant. The others, Dahlia Pseudodendron, Epiphytum and Entemophyllon, sometimes have growth characteristics that are unsuitable for beds, such as liana-like or very tall.

    The section Dahlia in turn includes 25 own species. There are now thousands of different breeds of varieties with countless flower shapes and colors. For the purpose of a better overview, they are therefore divided into 15 separate variety groups or classes, which are primarily based on the appearance of the flowers. The classes therefore often have names based on other plant blossoms, such as anemone-flowered or orchid-flowered dahlias.

    Here is a selection from the 15 variety groups, each with a variety example:

    ball dahlias

    As the name suggests, the varieties of this dahlia class show a spherical flower. They are a true classic among dahlias and an integral part of traditional flower gardens. Ball dahlias grow vigorously and reach a height of around 100 to 140 cm. The class includes a very colorful variety of varieties with delicate nude tones through to strong, radiant summer colors or multicolored structures.

    The Eveline variety, for example, has a white color with delicate violet hues, while the Golden Torch variety has a rich, sun-yellow ball of flowers. Fans of sophisticated play of colors within the flower might like the Jowey Joshua variety with its brick-red coloring with a cream-colored centre.

    Pompom Dahlias

    Characteristic of this class are the pompom-shaped, i.e. puff-shaped, spherical, double inflorescences. They are therefore quite similar to ball dahlias, but are not quite as large at around 80 to 100 cm. The neatly structured flower balls on the solitary stems make a very decorative picture. The different varieties can have very different colors - the Lipoma variety, for example, shows itself in romantic old pink to lilac colors from June and is also ideal as a cut flower.

    Cactus Dahlias

    With this variety, all those hobby gardeners who have a penchant for somewhat more exotic flower structures will get their money's worth. Because the cactus dahlias, with their many spherically arranged, pointed petals, give a somewhat less classic peasant, but somewhat more sophisticated picture. In some varieties, the prickly petal structure is further emphasized by a color transition at the petal tips - such as the Jessica variety, in which the lemon yellow center fades into a contrasting scarlet red at the ends.

    Deer Antler Dahlias

    The stag antler dahlias also show a particularly attractive flower structure with very numerous, dense and narrow-pointed petals, which, depending on the variety, sometimes appear very delicate and fringed. Again, there are a few different color variants with contrastingly tinted petal tips, such as the Anna Marie variety with a white heart and pink tips.

    Star Dahlias

    This variety shows a slightly less luxuriant inflorescence - with only a few, narrow petals in a regular star arrangement, they have a much more delicate appearance than the many voluminously filled types. The flowers have a diameter of about 8 centimeters, and the star dahlias can reach a height of a meter. The Honka variety is a particularly characteristic representative of the star dahlias due to its sun-yellow color with an orange pistil.

    Single flowering dahlias

    The eponymous simplicity of this class lies in the picture-perfect appearance of its open tubular florets with mostly 8 clear, ovate petals. Due to this open, easily accessible flower shape, the single-flowered dahlias are not only a feast for our eyes, but also for nectar-collecting insects such as bumblebees and bees. Their pollen supply is also very rich. The stature height varies quite widely within the class from a very low 30 to about 150 centimeters for hedge dahlias.

    The Karneol variety is one of the most well-known of the single-flowering dahlias and features bright red petals with slightly fading tips surrounding a rich yellow center.

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Vegetable garden