Pyrethrum blooms in May-June, and dewdrops are picked in batches after drying in sunny days. According to the research, when the inflorescence is yellow and the tubular flower in the middle has opened for 2 ~ 3 rounds, the content of pyrethrins is the highest.

After the flowers are picked, they should be dried or dried immediately, and they should not be piled together, otherwise they will ferment and rot. During the drying process, the moisture content is controlled at 7% ~ 65438 00%. Sealed, protected from light and stored. The yield per mu of dried flowers is generally about 50 ~ 70 kg, and the high yield can reach 80 ~ 100 kg, with a dry rate of 40%.