Cosmos Seed Planting Methods and Precautions

Cosmos is a variety of chrysanthemum, introduced and cultivated in China from abroad, and it can now be seen in many places across the country. Because of its high ornamental value, cosmos is deeply loved by people, and many want to grow it. Before planting, however, what everyone cares about most is surely its growing techniques.

How to Plant Cosmos Seeds

1. Sowing season. If you need it to bloom in summer, sow from February to March in early spring, and it is best to sow under conditions where both temperature and humidity can be controlled. If you plan to sow in the open air, sow in mid-April when the temperature is suitable; when the temperature is right, seedlings will emerge in about a week. If you need it to bloom in autumn, that is, to celebrate National Day, you can sow in July-August. Cosmos sown in this season has short, sturdy plants and is neat and beautiful.

2. Sowing soil. For the sowing medium, choose loose soil rich in organic matter, and apply a certain amount of decomposed organic fertilizer before sowing. When sowing, mix the seeds evenly with a certain amount of sand and sow evenly onto the seedbed, then cover with about one cm of soil. After sowing, keep the soil moist; germination occurs when the temperature is kept at about 18°C.

3. Sowing seedlings. When caring for the seedlings, once they grow 4 to 5 true leaves, they can be transplanted into nutrient pots and pinched. During the seedling growth period, no additional topdressing is needed, so as to avoid excessive growth of branches and leaves, which would affect flowering.

Cosmos Seed Planting Methods

1. Transplanting: Transplant when the seedlings have 4-5 true leaves, and pinch them; you can also thin the seedlings after direct sowing. If base fertilizer is applied to the planting site, then no further fertilization is needed during the growth period; if the soil is too fertile, the branches and leaves tend to grow excessively and flowering decreases. Those that bloom during the high temperatures of July to August do not easily set seed.

2. Light: Cosmos is robust, loves sunlight, tolerates drought, and has no strict requirements for soil, but it must not be waterlogged. If it is planted in fertile soil, it easily causes excessive growth of branches and leaves, affecting flowering quality.

3. Fertilizing: Transplant when the seedlings are 5 cm tall, and plant out when they have 7-8 leaves; you can also thin the seedlings after direct sowing. If base fertilizer is applied to the planting site, then no further fertilization is needed during the growth period; if the soil is too fertile, the branches and leaves tend to grow excessively and flowering decreases. Alternatively, during the growth period, apply decomposed urine diluted 5 times with water once every 10 days; in dry weather, water 2-3 times, and it will grow and bloom well. Those that bloom during the high temperatures of July to August do not easily set seed. After the seeds mature, they fall off easily, so collect seeds in the early morning.

4. Watering. Cosmos tolerates drought; after planting out, just water once thoroughly, and afterward water according to the wetness or dryness of the soil; if it is not dry, no watering is needed.

Precautions for Cosmos

It has no strict requirements for fertilizer and water; during the growth period, apply decomposed urine diluted 5 times with water once every 10 days. Tall and medium-height varieties need stakes before flowering to prevent lodging from wind damage; they grow quickly, so they can be pinched multiple times to increase branching. In hot weather, red spider mites are likely to occur, and early control is advisable.

Pest and Disease Control for Cosmos

1. Red spider mites: Cosmos is prone to red spider mites when it is hot and dry. Whether you like it or not, the probability of cosmos getting red spider mites is very high; even if you plant only two plants, there may still be red spider mites. Detect and control them early; at the initial stage, spray 40% dicofol emulsifiable concentrate at 1000 to 1500 times dilution.

2. Powdery mildew: Do not plant too densely; maintain good ventilation and light transmission. After the disease occurs, promptly cut off and destroy diseased leaves and diseased plants, and strictly prevent reinfection. At the initial stage, spray 15% triadimefon wettable powder at 1500 times dilution, or 10% lewubing wettable powder at 1200 to 1500 times dilution; use the two medicines alternately and spray 2 to 3 times in succession.

Cosmos is best sown in early spring each year. When planting, choose suitable soil; cosmos does not tolerate waterlogging, so doing a good job of drainage is also essential. In the later stages of planting, pest control must be strengthened; only in this way can cosmos grow well.