How do you plant dahlia seeds, and when do they bloom?
Dahlia is surely familiar to many people. It is a highly ornamental plant, and its main ornamental appeal lies in its flowers, which are commonly seen in white, red, yellow, pink and other colors, bright and rich, very eye-catching. Many people grow dahlia now, and before planting, everyone should still have a comprehensive understanding of its growing techniques.
How to plant dahlia seeds
1. Dahlia seeds are generally sown in early May. The seeds are sown by dibbling or drilling in flower pots or a seedling bed, then lightly covered with a layer of 0.3 cm of soil. Keep the temperature between 15°C and 20°C, and control humidity and sunlight at around 70%. Generally, they will sprout in six to eight days, and after two leaves have grown they can be planted out.
2. After planting out, the temperature needs to be kept between 18°C and 25°C. When five to seven true leaves have grown, the seedlings can be transplanted. When transplanting, note that the seedlings must be moved with their original soil, which can effectively avoid damaging the dahlia's tuberous roots and helps them survive. The distance between the transplanted seedlings should be kept between 20 cm and 30 cm.
When dahlia blooms
In fact, in a suitable place, this plant can bloom all year round, and its flowering period is very long. However, in regions with distinct seasons, its flowering period is generally concentrated from May to October.
Care after dahlia blooms
1. Arrangement of light. The growth of this plant greatly needs plenty of light. In the three seasons of late autumn, winter and spring, because the surrounding temperature is not too high, it can be left directly exposed to the sun, which helps its own biological processes, better forming flower buds and then blooming. If it is in the hot summer, we probably need to shade about 30 percent of the sunlight for it. After blooming, it can be placed indoors for viewing, and it should be placed beside a doorway or window facing southeast, which can delay its flowering period and also increase the number of its blooms.
2. Arrangement of temperature. This plant very much likes cold and cool temperatures and is most afraid of hot temperatures, so generally in summer it will slowly stop growing; at the same time, it cannot accept too low a temperature either. When the temperature is lower than the humidity, it will begin to go dormant. Generally speaking, the most suitable temperature for it is 15°C to 28°C. As long as the daytime temperature does not exceed 28°C, and the temperature difference between day and night is also relatively large, flower buds will differentiate more easily.
Dahlia pests and diseases and their control
1. Powdery mildew. Dahlia usually develops powdery mildew in September and October. When the disease occurs, some chemicals can be sprayed, such as a diluted solution of antimycin or a diluted solution of sulfur-multi suspension concentrate, etc. Spraying several times in succession will have a therapeutic effect.
2. Brown spot. When dahlia develops brown spot, the disease is generally more severe from June to August. Bordeaux mixture or chlorothalonil solution can be used for treatment.
3. Viral disease. Viral disease is also a common disease of dahlia, mainly showing symptoms such as mosaic leaves, leaf chlorosis, and plant dwarfing. Dahlia develops viral disease mainly because it is infected by some viruses, producing pathological changes. When growing dahlia, choose some pest- and disease-free planting material, and prevent insect pests.
4. Snout moth larvae. When dahlia is damaged by snout moth larvae, some fenitrothion insecticide can be sprayed for treatment. Omethoate insecticide can also be injected.
When planting dahlia, a suitable time should be chosen, and after planting, temperature management needs to be strengthened. Too high or too low a temperature may cause growth problems for the plant. After growing it, care needs to be strengthened, especially the prevention and control of pests and diseases, so that dahlia can grow better.