Dahlias are the undisputed queens of the second half of summer and autumn. They bring a lot of positive energy to the discount. There is something for everyone among the innumerable varieties. And there is a lot to choose from. The generic name dahlia Dahlia was given in honor of the Swedish botanist Andreas Dal. Often referred to as Georgina, they represent the broad family of Compositae. They came to Europe in the late 18th century from the highlands of Mexico and Guatemala. The vast majority of varieties were created from the crossing of two species: Dahlia pinnata and Dahlia coccinea.The first breeding work showed extraordinary variability and ease of interbreeding, which led to the creation of a large number of varieties.
Dahlias are perennials that do not winter in the ground. The aboveground part can grow up to 30 cm in dwarf varieties, and up to 180 cm in the tallest varieties. Shoots are fleshy, hollow, branched. Dark green leaves, pinnate, toothed at the edges. The underground part is a bundle of storage roots, called a carp.As there are currently over 2,000 registered varieties, it was necessary to systematize them according to two most important criteria: height and type of flowers.Depending on the height, we can distinguish dwarf dahlias, reaching from 20 to 40 cm; medium tall - up to 120 cm and very tall (from 120 to 180 cm).
The division of dahlias by type of inflorescence is a real floral kaleidoscope. A distinction is made between single-flower dahlias. The center of the basket, composed of yellow tubular flowers, is surrounded by a single lingual flower whorl. Plants in this group are usually dwarf varieties. Half-double forms have two or more whorls of lingual flowers.Here we distinguish peony and anemone dahlias. Full-flowered dahlias are the most numerous group - all flowers are transformed into petals.
In comb varieties, they resemble water lilies; decorative dahlias can boast the largest flowers, up to 30 cm in diameter; pompoms resemble beautiful balls; Cactus plants have narrowed petals, which makes them look very exotic, just like orchid dahlias. The color palette is almost unlimited.Only blue and black are missing, although growers have already come very close to these colors.Flowers can be single, double and tricolor in all possible combinations.
Growing dahlias
Dahlias are not difficult to grow plants, but it is worth trying a bit to fully display their beauty. As befits a native Mexican, they grow he althy and bloom profusely only in full sun or only light shade.Only there they reach their target size and the flowers have a saturated color.The soil should be light, permeable, rich in nutrients, always slightly moist, neutral or slightly alkaline.Dahlias definitely don't like acidic soils. In the full growing season, they should be watered regularly, because they react very quickly to water shortages with wilting. Tall varieties can then break.
You should think about the cultivation site in autumn and dig the soil with a large amount of decomposed manure or compost. Alternatively, in spring, when planting carp, it is worth sprinkling multi-component fertilizer, and if necessary, be on poorly fertile soil, fertilize once a week with florovit during the development of shoots.Be careful not to provide the plant with excess nitrogen, because then the shoots will be excessively exuberant and flowering noticeably weakened.Plants overfertilised with nitrogen are more likely to be attacked by pests, especially aphids.
Tall varieties of dahlias should be planted in places sheltered from strong gusts of wind to prevent them from breaking off. It is also good to use supports, for example in the form of stakes, and tie the shoots as they grow.
Dahlia carps should be planted into the ground in mid-May in wells filled with fertile soil, evenly spreading the thickened roots.The top should be covered with a 5 cm layer of soil.You can also drive plants in your home or greenhouse in separate pots. Such specimens will flower approximately 3 weeks earlier. Dahlias are very sensitive to the slightest frost, so in the event of the forecasted night temperature drops, plants need to be covered with jute, non-woven fabric, newspaper or cardboard.
Solo or in a group?
Dahlias look great solo, especially the tall varieties, and also in the company of other varieties or with other summer flowers such as mallow and marigolds.Planting them at the right spacing is important. . For the smallest it should be 20-30 cm, the higher ones every 50 cm, and the largest even at 1 m intervals. Thanks to this, dahlias do not risk being "suffocated" by neighboring plants.
Low dahlias are perfect for bowls and pots on terraces or for the border of a rebate.The taller varieties can be used to create floral hedges or multi-colored compositions, while the tallest ones can be a background for less impressive flowers.It is interesting to combine them with vegetables, for example with leaf beets, fennel or kale.Dahlia flowers are also perfect for a vase where they last for about 5 days.
Beware of aphids!
Dahlias are resistant to diseases and pests, although you need to closely monitor for the appearance of aphids and intervene immediately if necessary. It is important to combat them because they can carry dahlia mosaic that induce growth stunting and cucumber mosaic, which shows yellow spots on the leaves.Sick specimens should be excavated and burned so that they do not become a source of disease spread.In more rainy, humid summers, the plant can be attacked by gray mold.
Dig out and split carp
1. In autumn, when the first serious frost weighs in the aerial part, it is a signal that it is time to dig up the stumps.The best for this purpose is a pitchfork, which you should first use to slightly loosen the soil around the plant.
2. The shoot is shortened to about 10 cm and left to dry in a ventilated place for 10 days.
3. When the stumps are pre-dried, shake them off the excess soil, then arrange them with the roots upwards, sprinkling them with slightly damp peat or sawdust to prevent them from drying out.It's a good idea to soak them in a fungicide solution for an hour.
4. The stumps are labeled with the name of the variety or the color of the flowers. We store them over the winter in a frost-free room at a temperature of about 5 ° C, checking their condition from time to time. When they become excessively dry and wrinkled, they should be lightly sprayed, and the specimens affected by pathogens should be disposed of immediately.During spring planting, the stumps can be divided so that each fragment has at least one well-developed bud.
What is the best way to protect dahlias after excavation?
Dahlias are native to Central America (sunny Mexico), beautiful and profusely flowering perennials from the Asteraceae family. Unfortunately, they are sensitive to frost and in our climatic conditions they do not winter in the ground. Preparing dahlias for winter dormancy should be started well in advance. At the end of summer (turn of August and September), watering of the plants should be limited so that they start storing nutrients in the tubers. Dahlias are dug up after the first frost after cutting the above-ground part of the plants approx. 5-8 cm above the ground level. After removing the remains of the substrate and damaged tubers, dry the stumps, and then place them in openwork, airy containers (e.g. boxes or wicker baskets) and sprinkle them with sand or earth. Dahlias are best wintered indoors at a temperature of approx. 5 ° C (not lower than 0 and not higher than 10 ° C).
- says Dr. Eng. Tomasz Mróz
