The genus of Dahlias (Dahlia) from the family Compositae includes, according to various sources, from 4 to 24 species of perennial tuberous plants. They come from the mountainous regions of Mexico, Guatemala, Colombia. Ancient Indians grew wild chrysanthemums for the sake of their corms, which they ate for food. However, once in Europe, they began to be used as ornamental plants to create rabatok, borders, massifs, as well as free compositions and group plantings.
For the first time, European flower lovers met them in 1787, when the first dahlias were grown by the Director of the Madrid Botanical Garden A. Cavanilles from seeds sent to him from Mexico. From there, they spread throughout Europe, becoming one of the most fashionable flowers.
Today, most often in the gardens of our climatic zone, one can find a variable dahlia (Dahlia variabilis) with its many forms, blooming in late summer and autumn.
Dahlias - growing and care
Dahlias grow best in sunny, sheltered from cold and strong winds areas with good air circulation, which are illuminated by the sun for at least 6 hours a day. Low and wetlands for breeding these plants are not suitable, therefore, if the groundwater level exceeds 60 - 70 cm from the soil surface, it is necessary to raise the level of flower beds.
Dahlias need fertile structural and moisture-intensive soil. In a pit for planting, the size of which should be 40X40 cm, it is necessary to put a third of a bucket of manure, mixing it with light humus soil, 20 gr. superphosphate and 1 tbsp. a spoon of ash.
The frequency of watering a dahlia is determined by the ambient temperature and soil moisture. During the growing season, the soil should be loose and clean from weeds. It should be loosened after each watering or top dressing. With the formation of buds, loosening should be stopped and the soil should be mulched with humus or peat.
Feeding dahlias is carried out based on soil fertility and plant development. As a rule, they are fed for the first time 2 weeks after planting at the place of constant cultivation with a solution of 10 liters of water and 1 liter of mullein with 1 tbsp. urea spoon. For the second top dressing, which is carried out after another 10-12 days, use a solution of 10 l of water, 2 tbsp. urea and 1 tablespoon of complex mineral fertilizers. The third top dressing, which coincides with the period of budding, is carried out with a solution prepared from 10 l of water taken with 1 tbsp. spoon with potassium sulfate, superphosphate and nitroamophos. The fourth feeding is carried out in mid-August. To prepare a solution in 10 l of water, you need to dilute 2 tbsp. tablespoons nitrofoski and 1 tbsp. a spoonful of superphosphate. When buds appear on a plant, it needs to be sprayed several times with a growth regulator, maintaining an interval of one week between treatments.
In order for the dahlias to have good inflorescences, their bushes are formed by removing shoots that grow from the root neck during the growth period and breaking down stepsons in the form of side shoots growing in the axils of the leaves. If this is not done, then the flowering of the plant will be later and weaker.
In October should be cleaned dahlias for winter storage, which is usually carried out in the basement, at a temperature of 4 ° C to 8 ° C and a humidity of 70%, where they are placed in slightly moist peat or sand. You can store dahlia bulbs in the apartment, providing them with appropriate conditions. During storage, it is necessary to inspect tubers, bulbs, rhizomes at least twice a month in order to remove dead plants and foci of diseases in time.
Dahlias - transplantation and reproduction
In the midland, dahlias can be planted in open ground, starting from the end of the first decade of June, when it is no longer possible that frost can return. Plants in a row should be spaced about 60-100 cm apart, and the row spacing for group planting should be at least 100 cm. The root tuber's neck should be buried in the soil when planting 4-6 cm. Plants grown by dividing the root tubers and cuttings, before planting, you need to pour plenty of water, then transfer with a lump of earth into the prepared hole. When planting, you should immediately drive in a stake up to one and a half meters long, which will later be used to garter the plant.
Dahlias are propagated by cuttings and dividing root tubers. Cuttings are carried out from late February to early March, and in April, rooted cuttings are planted in pots with a diameter of 8-10 cm and shaded for several days. A plant is ready for planting in the soil, if its shoot height is from 20 to 30 cm, and the root system is well developed. Those who did not have the opportunity to cut dahlias in February-March can do this in April, by planting tubers in the soil of warm greenhouses or greenhouses and cutting the cuttings in the same way as in February. The height of the soil layer should be at least 15 cm. For better rooting, the cuttings need periodic spraying with water from the spray gun and shading.
Dahlias - possible diseases and pests
Dahlias can get sick with viral mosaic, powdery mildew, and bacterial cancer. The viral mosaic can be recognized by the appearance of light green spots of various shapes and sizes on leaf blades. Also, the disease leads to a shortening of the internodes and peduncles, dwarfism of the plant, a decrease in the brightness of the color of the petals. Unfortunately, it will not be possible to cure diseased plants, they will have to be dug up and burned. Bacterial cancer affects the tubers of the plant, and it can be detected by autumn digging a dahlia. It is manifested by the formation of ugly buds and growths up to 12 cm in size on the root neck of diseased plants. Affected tubers must also be burned.
Dahlias can also be affected by pests: slobbery pennies, aphids, flower beetles, slugs. They fight aphids with garlic infusion, onion husk infusion, spraying with chlorophos (10 g per 10 l of water), dusting wet leaves with ashes. Powdery mildew, slobbery pennies, as well as aphids and flower beetles are fought against by spraying with urea (50 g per 10 l of water), which is carried out in the evening or in cloudy weather. So that the plant is not overcome by slugs, it is necessary to sprinkle the paths adjacent to the plantings with iron or copper sulfate, which are 1 square meter. the meter is used up to 10 gr., or superphosphate (30 gr. per 1 sq. meter). You can also treat the leaves with 10% decoction of capsicum.
