Aster "Kriemhild"

Propagation: by seeds. Seeds remain viable for 2-3 years. Sowing can be done both in the open (in autumn and spring) and in protected ground (for a month, starting from mid-March).
For seedlings, mid-late and late flowering plants are sown in a warm room in boxes (second half of March). The soil is prepared in advance; it should be nutritious, breathable, and retain moisture well.
Here are possible options, for example: turf soil, river sand, humus (3:1:0.5); turf soil, humus, sand (2-3:1:0.5); turf soil, peat, sand (1:2:2). The sand must be washed and calcined in the oven at a temperature of +80°C.
Before sowing, the soil in the box is watered with a hot solution of potassium permanganate (2 g per 10 l). These measures will protect plants from the disease "black leg".
1,0 g = 450 seeds.
The seeds are sprinkled with dry finely sifted humus (a layer 0.5 cm thick) and watered. The crops are covered with polyethylene film, until the shoots appear, the room temperature is maintained at +18 +20 °C. The next time they are watered after the shoots appear (the seeds germinate on the 3rd-10th day). In order for the seedlings to grow and develop normally, the temperature should not be below +15 °C.
The seedlings are planted in open ground in late May - early June. The soil under the asters should be fertile, permeable to moisture, since the plants do not tolerate stagnant water. Before planting, humus, wood ash, compost are added, but in no case fresh manure. 
When planting seedlings, care must be taken to ensure that the roots do not bend and that the growth point is not covered. Tall varieties with a wide bush are planted at a distance of 30-40 cm from each other, medium-sized ones - 20-25 cm, dwarf ones - 10-15 cm. When planting, the plants must be "squeezed", and the damp soil around them must be sprinkled with dry soil. Further care is normal - timely watering, weeding and loosening. 
Early and mid-flowering plants are sown in early April in the soil of a heated film greenhouse or in hotbeds. The soil is prepared 1-2 weeks before sowing: humus is added and dug up, leveled with a rake, ridges 1 m wide are made, and then watered with a hot 0.2% solution of potassium permanganate at the rate of 1 bucket per 1 m2. 
After this, cover with polyethylene film, which helps to retain heat and moisture, and also provokes the germination of weed seeds. To get rid of their shoots, after 3-6 days the soil is dug up or loosened with a rake. If there are a lot of weed seeds in the soil, then the procedure is repeated once more. This technique allows you to grow seedlings with virtually no weeding. If weeds do appear, then they are selected when thinning out the aster crops. 
The prepared soil is loosened again on the day of sowing, lightly tamped and marked (5 x 5 cm or 6 x 6 cm). After sowing, the seeds are sprinkled with earth or finely sifted humus, watered with water at room temperature and covered with polyethylene film, which is not removed until shoots appear. 
Subsequently, the seedlings are watered with warm water to avoid the appearance of root rot. The temperature in the greenhouse should be around +18+20°C, air humidity 70-80%. The seedlings are planted in prepared soil.
The crop is cold-resistant, tolerates frosts down to -3..-4°C. Plants obtained from seeds during winter sowing begin to bloom in open ground 10-14 days later, and during spring sowing (April) - 14-17 days later than plants hatched from seedlings, however, their flowering is more abundant and lasts longer.
Use: depending on the height of the stem and the decorativeness of the inflorescences, asters are suitable for flower beds, group plantings and borders in the garden or for decorating balconies and terraces.