Dahlia – the queen of late summer

Hibernation

Since dahlias are sensitive to frost, they must overwinter indoors. With the first frosts, the flowers' original color disappears, and they turn brown-yellow. Then you can cut the plant back to a height of five to six centimeters. Leave the tubers in the soil for a few more days so they can absorb enough nutrients from the stems to survive the winter. This gives the tubers enough time to ripen properly and bloom even more vigorously the following year. A few nights of light frost will not harm the plant. When you dig up the plant, the soil should be as dry as possible, as it will then separate more easily from the tubers. Before storing, inspect the tubers for rotten spots and cut them out if necessary. A frost-free room that is not too humid, but also not too dry, with an average temperature of around +6 degrees Celsius is ideal for overwintering. It is recommended that you label the tubers with the colors and varieties. You can then replant them in May, based on their color.

A class of its own

Doubts can sometimes arise: Do the different creatures all belong to the same family? Some look prickly, others like discs, some flowers are truly spherical. Dahlias also vary considerably in size: some have a diameter of 4 to 5 cm, while giant specimens reach a diameter of 30 cm and more. Breeders can produce a suitable dahlia for every trend. Thirteen different classes of dahlias are distinguished depending on the shape of their flowers.

• Simply flowering dahlias: They bear single or only slightly double flowers. The center forms a flat, round disc. They most closely resemble their wild relatives from Mexico. They also withstand rainy weather.
• Anemone-flowered dahliashave flower heads with one or more outer rings of mostly flat petals. The center is a dense cluster of long tubular flowers.
• Collar dahliasThey are similar in structure to single-flowered dahlias, but also have a ring of smaller individual flowers. This contrasts in color with the lower petals.
• Water lily dahliasThey are very similar to aquatic plants. They have double flowers (similar to decorative dahlias). They are characterized by large petals that are straight or slightly curled inward or outward around their longitudinal axis.
• Decorative dahliasare also known asOrnamental dahliasThey have densely filled flowers that do not have a disc.
• Ball dahliashave densely filled, ball-shaped flowers. The petals are rounded at the tip and curled over more than half their length. The shape of a flattened apple is considered perfect. They are significantly larger than pompom dahlias.
• Pompom dahliasWith their tightly rolled leaves, they form compact, homogeneous spheres that are even more rounded and considerably smaller than the ball dahlias.
• Cactus dahlias: Their petals are twisted outward, thin, and pointed. Some cactus dahlias delight with their plate-sized, fuzzy heads.
• Semi-cactus dahliasThey are notable for their pointed, elongated petals. The petals of the semi-cactus dahlia are slightly narrower than those of the decorative dahlias, but wider than those of the cactus dahlias.
• Various dahliasare all dahlias that cannot be assigned to any other class, e.g. peony-shaped dahlias.
• Staghorn dahliasTheir blooms often resemble cactus or semi-cactus dahlias. Their split flower ends are frayed.
• Orchid-flowered dahliasSimple dahlias have only one flower crown arranged in a star shape (hence the name star dahlias). The flowers are usually curved upwards.
• Orchid-flowered dahlias filledThey have a graceful shape. The fully double flowers are curled upwards or downwards. Like the single orchid-flowered dahlia, the double variety is a cultivar for enthusiasts.

Concentrated beauty

You don't necessarily need a garden to enjoy the splendor of dahlias. They also thrive in tubs or window boxes, adding a nostalgic touch. These are usually shorter varieties with rather small flowers. The taller the variety, the larger the container should be. Potted dahlias can be planted in beds at any time. Since dahlias require a lot of nutrients, it's advisable to mix slow-release fertilizer into the potting soil when planting.
The dahlia also makes a great cut flower! The plump blooms attract attention and spread cheer. Even a single blossom makes a wonderful table decoration. A dahlia doesn't necessarily need a companion to be effective.
To ensure they bloom long in a vase, they should always be cut early in the morning. This is when the stems and blossoms are still saturated with water. Don't cut the flowers too close to the buds; unlike roses or tulips, they won't bloom much further in a vase. Regular "harvesting" doesn't harm the plant—in fact, it acts like pruning, stimulating the dahlias to produce new flowers. After cutting, all leaves should be removed from the stems; this reduces the evaporation surface and increases the life expectancy of the flowers. To ensure they last longer in a vase, cut the stems diagonally and change the water daily.

TEXT: Victoria Wegner