When does hollyhock usually blossom? What are the main points of common pest control methods?

Hollyhock, also known as Yizhanghong, military sunflower, etc., has been planted all over the world. It has a wide variety of colors and unique patterns, and has a certain ornamental value. Hollyhock flowers and leaves are edible, can be used as medicine, with heat-clearing, diuretic and other effects. When does the hollyhock usually bloom? What are the main points of common pest control methods?

When does hollyhock usually blossom?

Hollyhock florescence from February to August, planted in the first year, can blossom in the second year, can bloom for many years in a row. The hollyhock sown in September has been growing and developing in the second year, and if the ripe time has missed the flowering period, then the flowers can only be seen in the third year. However, if the method of ramet cuttage is used, then flowering can be seen in that year, and it grows very fast.

Second, what are the main points of prevention and control of common diseases and insect pests of hollyhock?

The common diseases of hollyhock include white spot and brown spot of hollyhock.

1. White spot of hollyhock

Symptoms: White spot mainly harms the leaves of hollyhock, and there are small brown spots on the leaves at the initial stage of the disease. with the development of the disease, the spot gradually expands into round, oval or irregular shape, the center of the spot is grayish white and the outer edge is reddish brown. There is a grayish-brown mildew layer on the disease spot in a humid environment.

Incidence regularity: White spot disease is caused by Cercospora infection of half-known hollyhock. The pathogenic bacteria overwintered on the soil and diseased bodies with mycelium and conidia, and the conidia were transmitted by wind, rain or watering. The disease began in the middle and last ten days of June, and the peak period was in July and August, especially in the period of high temperature and humidity, which could be infected repeatedly and formed three peak periods in a year.

Prevention and treatment methods: the diseased leaves can be removed in time, pay attention to the density of branches, make the plant keep ventilated and transparent; increase the application of phosphorus and potassium fertilizer, little or no nitrogen fertilizer; at the initial stage of the disease, spray 75% chlorothalonil wettable particles 800x or 50% carbendazim wettable granules 1200 times or 70% methyl thiophanate wettable particles 1200 times spray, once every 10 days, continuous spraying for 3 times can effectively control the disease.

2. Red spider

There are red spiders during the growth period.

Prevention and control methods: when the occurrence of serious, with 1.8% avermectin EC 7000 to 9000 times liquid uniform spray control, or the use of 15% paraben EC 2500 to 3000 times solution has a better control effect. Do not use dichlorvos to kill mites. Dichlorvos can stimulate the proliferation of mites. Do not use pyrethroid pesticides, which are basically ineffective against mites.

3. Borer

Sometimes the cotton leaf roller harms the leaves of hollyhock.

Prevention and control methods: when it occurs, it can be sprayed with 16000IU/ mg Bt wettable powder solution, or 25% diflubenzuron suspension 1500 to 2000 times, or 20% Miman suspension 1500 to 2000 times, and so on.