Annual chrysanthemum
Annual chrysanthemum is an annual or biennial herbaceous plant in the Asteraceae family, genus Ismelia. The stems are erect and much branched, and the plant grows 30 cm to 70 cm tall, with bipinnately parted leaves. The flower heads are capitula, and the corollas come in red, pink, yellow, white, purple and other colors, often with two or three colors forming a multicolored ring; the flowering period is from June to September.
Annual chrysanthemum is native to Morocco in North Africa. It prefers a cool climate, with a suitable growing temperature of 15°C to 25°C, and is not particular about soil; garden soil, slightly acidic soil and sandy loam can all support its growth. It is propagated by sowing, and can be sown in spring or autumn. After the seeds are harvested, they are first dried in the sun, and after the impurities are removed, they are stored in a refrigerator at 0°C to 5°C and taken out again at sowing time. Annual chrysanthemum seeds are relatively small, and after sowing they are generally not covered with soil, but plastic film should be placed over the seedling tray to prevent moisture loss and also to provide insulation. Generally speaking, they germinate 7 to 10 days after sowing. After 3 to 5 true leaves have grown, the seedlings are transplanted; they can be grown in pots or planted directly in the open field, with a plant-to-row spacing of 20 cm × 25 cm being suitable. During the growing period, a topdressing should be applied once every two weeks; dried chicken manure or compound chemical fertilizer is suitable, and the fertilizer should be applied in an appropriate amount, while watering should also be done in a timely manner.
Annual chrysanthemum has brilliant flower colors and a long flowering period. In gardens it is mostly used to arrange flowerbeds or flower borders, and it can also be grown in pots for ornamental viewing. For indoor potted cultivation, it is best to first carry out dwarfing treatment; when the seedlings are about 10 cm tall, chlormequat (at a concentration of 0.1%) can be smeared on the stems, applying the solution once every 10 days, and stopping the application once the flower buds have formed. In this way, the seedlings are only about 20 cm tall, and can be used to decorate a study or living room. Annual chrysanthemum can also be used as a cut flower material, combined with lilies, roses and carnations to make flower baskets or bouquets.