CATDOLL : CATDOLL: What to do if Cosmos is infested with insects

1. What should I do if the cosmos is infested with insects?

It depends on what kind of insect it is. If it is aphid, you can use imidacloprid. If it is red spider, use avermectin.

2. Disease and Pest Control of Cosmos

Its main diseases and insect pests are leaf spot and powdery mildew. Red spider mites are more likely to occur in hot weather, so early prevention and control is recommended.

Powdery mildew: Symptoms occur on leaves, tender stems, flower buds and buds, etc. The obvious feature is the growth of gray-white powdery mold layer (conidia and mycelium of the pathogen) on the diseased plants. The growth and development of the affected plants are stunted, the leaves are twisted, and they cannot bloom or the flowers become deformed. When the disease is serious, the leaves dry up and the plants die. It belongs to the subphylum Ascomycota. The mycelium grows on both sides of the leaves, the conidia are columnar, the ascocarps are aggregated or nearly aggregated, dark brown, flattened spherical, the appendages are unbranched or irregularly branched, curved, the asci are long or short ovate, and the ascospores are oval or elliptical. The asexual stage of the pathogen is powdery spore (Oidiumery siphoides Fr.). The pathogen overwinters on the diseased buds and branches of the host as mycelium, and produces a large number of conidia the following year, which invade the host to absorb nutrients after germination.

Prevention and control methods: Apply appropriate amount of phosphorus and potassium fertilizers, pay attention to ventilation and light transmission; promptly cut off seriously diseased plants or seriously diseased parts, bury them deeply or burn them to eliminate the source of bacteria; if necessary, spray 1500 times diluted 15% triadimefon wettable powder at the early stage of the disease.

3. Can I grow cosmos at home?

Cosmos is an annual herb with a height of 1 to 2 meters. Its flowers come in pink, white, purple and other colors. Its flowering period is from June to October.

Cosmos is strong and adaptable. It likes plenty of sunlight, is not cold-resistant, nor heat-resistant, but is drought-resistant and barren-resistant. It grows well in fertile, loose, moist and well-drained soil. But it should be noted that too much fertilizer and water can easily cause leggy growth, lodging and fewer flowers.

It is propagated by seeds, usually sown in spring, with fewer flowers in summer and a large number of flowers in autumn when the daylight is short. Pruning can be done in summer to make the plants shorter and prevent them from falling over. Cosmos is suitable for extensive management and has a strong ability to reproduce by self-seeding.

In gardens, cosmos is often cultivated in large quantities on the roadsides of streets, railways, and highways, or used in flower arrangements and flower borders, and can also be used as cut flowers.

4. What should I do if my blue-eyed chrysanthemum and marigold are infected with red spider mites?

I have the same problem... There are a lot of red spider mites on my dwarf tomatoes, but I used some medicine recently and it's gotten much better. You can also buy some medicine and spray it on them.

5. Cosmos planting method

Propagated by sowing or cuttings.

Cosmos is propagated by seeds. In northern my country, seeds are usually sown from April to June, and flowers bloom from June to August. The climate is hot and rainy from August to September, so fewer flowers bloom. After the cool autumn, flowers continue to bloom until the frost falls. If sown in July and August, they can bloom in October, and the plants are short and neat. Cosmos seeds have the ability to self-sow. Once planted, they will produce a large number of self-sowing seedlings. If they are slightly protected, they can bloom as usual. They can be sown in the open field in mid-April. If the temperature is suitable, the seedlings will emerge in about 6 to 7 days. Cutting propagation is possible during the growth period. Cut the strong branches about 15 cm below the nodes and insert them into sandy loam. Proper shade and humidity are maintained, and roots will take place in 6 to 7 days.

In the central and southern regions, it is sown in April and germinates quickly, 7-10 days after sowing. It can also be propagated by softwood cuttings, which will take root 15-18 days after cutting.

Transplant the seedlings when they have 4-5 true leaves and pinch off the top. Thinning can also be done after direct seeding. If the planting site is fertilized with basal fertilizer, no further fertilization is needed during the growing season. If the soil is too fertile, the branches and leaves will grow too long and the flowering will decrease. Those that bloom during the high temperature period of July and August are not likely to set fruit. Cosmos is a short-day plant. Spring-sown seedlings tend to have lush branches and leaves but fewer flowers. Summer-sown seedlings are short, neat, and bloom continuously.

Cultivation management

Cosmos is strong, likes sunlight, is drought-resistant, and is not very demanding on soil, but it cannot be waterlogged. If it is planted in fertile soil, it will easily cause the branches and leaves to grow too long, affecting the quality of flowering.

Transplant when the seedlings are 5 cm tall, and plant when they have 7-8 leaves. Thinning can also be done after direct seeding. If the planting site is fertilized with basal fertilizer, no further fertilization is needed during the growing period. If the soil is too fertile, the branches and leaves will grow too long and the flowering will decrease. Alternatively, apply 5 times the amount of decomposed urine every 10 days during the growing period. Water 2-3 times during drought, and the plant will grow and bloom well. Those that bloom during the high temperature period of July-August are not easy to set seeds. The seeds are easy to fall off after maturity, so they should be collected in the early morning. Cosmos is a short-day plant. Spring-sown seedlings often have lush leaves and few flowers, while summer-sown seedlings are short, neat, and bloom continuously. It grows rapidly and can be topped several times to increase branches.

Cosmos plants are tall, and when planted in the windward area, support should be set to prevent lodging and damage. Generally, they are cultivated into dwarf plants, that is, the tops are removed when the seedlings are 20-30cm tall, and the new terminal buds are removed several times in succession, so that the plants can be dwarfed; at the same time, the number of flowers is also increased. It is advisable to apply a little basal fertilizer to the planting nursery. It is advisable to pick seeds when the achenes turn slightly black to avoid scattering after maturity.

Cultivation:

This species needs short-day treatment during the seedling stage to bloom normally, and the appropriate sowing time should be mastered; it is suitable for direct seeding in the open field, and can also be used for seedling raising; sowing is covered with soil about 1cm, and the seedlings will emerge in about 5-10 days; the seedlings are transplanted when they have 5-6 true leaves, and the planting distance is 30-50cm. During the growth period, pinch the top to promote branching, and control the height to avoid lodging in the later stage. It is not strict with soil requirements, but it cannot accumulate water, is not cold-resistant, and avoids extreme heat. It can tolerate poor soil.

Maintenance points

Propagation: Sowing or cuttings. Cuttings can also be used in summer. Sowing in late March or early April, sow the seeds in an open-air nursery. Germination is possible at a low ground temperature of 15°C, but if sown too early, it will grow into a giant plant 2m tall, which will easily fall over due to typhoons or the weight of the plant. There are also early-blooming varieties that bloom 50-70 days after sowing, so sowing should be done separately for early and autumn blooms.

Management: It likes warm and humid weather and is sunny. It is slightly resistant to early frost and has no strict requirements on soil. The seedlings can be transplanted when they are 5 cm tall and planted when they have 7-8 leaves. It has no strict requirements on fertilizer and water. During the growth period, apply 5 times the amount of decomposed urine with water every 10 days. For medium and high-sized varieties, support pillars should be set up before flowering to prevent wind disasters and lodging. It grows rapidly and can be topped several times to increase branches. Red spider mites are prone to damage in hot weather, so it is advisable to prevent and control them early. If sown in late July to early August, it will bloom after 50-60 days. The plants are short and neat and can be used for National Day. If you want to cultivate short cosmos that will not lodge, you should take the following measures:

①Sowing in late July.

② After spring sowing, pinch off the top when the plant grows to 40-50cm to allow the axillary buds to bloom.

③Erect dwarf bamboo and other supports as soon as possible.

Diseases and pests: Be sure to take measures to deal with mildew, aphids, and spider mites. Spray benomyl for mildew and Ortolan granules for pests.

How to prevent Cosmos from falling over? Cosmos has a relatively tall and sparse plant shape, and large and beautiful flowers. However, it often falls over, which ruins the scenery. To prevent Cosmos from falling over, the following measures can be taken:

①Sow the seeds in July and August. Cosmos sown during this period will bloom in October, and the plants will be short and neat.

② Pinching. Pinching is necessary during the growth period of Cosmos. On the one hand, it can shorten the whole plant, and on the other hand, it can promote the germination of branches and increase the number of flowers.

③ Apply less fertilizer and water. Too much fertilizer and water can easily cause the plant to grow too tall and fall over, and the flowers will be sparse.