How to grow ornamental sunflowers?

Ornamental sunflower is an annual flower of the genus Compositae, with a plant height of 90 to 300 centimeters, flowering from July to September, with golden yellow, red and complex colors, etc., generally planted in pieces, golden when blooming, both wild and spectacular, widely used in cut flowers, potted flowers, dyed flowers, courtyard beautification and flower border construction and other fields. Let's take a look at how to grow ornamental sunflowers.

Growth habit

Ornamental sunflower originated in North America, like warm, slightly dry and sunny environment, drought tolerance, but pot can also be cultivated in the open field. The long light time of open field cultivation often blossoms a little earlier, and the temperature difference of 8 to 10 ℃ is the most favorable for stem and leaf growth. Most of them are single-petal varieties, and there are also double-petal varieties. Take potted dwarf species as an example, it takes 50-60 days from sowing to flowering.

Reproduction method

Ornamental sunflower seedlings are sown and propagated by sowing, which is usually sown in April. The optimum temperature for germination is 15-18 ℃, which can be sowed in shallow pot or shallow box, with loose medium, good water retention, asepsis and so on. Sowing on demand is appropriate, sowing 2 grains per hole, covering 1 to 2 cm thick medium after sowing, in order to maintain the humidity needed for germination, increase the stability of seedling stage and reduce the occurrence of shelled seedlings. Generally germinate 7 to 14 days after sowing, pay attention to ventilation and cooling after emergence, control humidity, and gradually see the light.

Timely planting

Ornamental sunflowers can be planted when the seedlings are full, leaving 1 plant in each hole, and the seedling height is 7 to 8 cm. The basin soil should be sandy soil which is rich in humus and well drained. When planting, apply sufficient basal fertilizer to the bottom of the basin, and dig up the seedlings with more soil and less root damage, so as to make the plant recover quickly.

Planting management

1. Light: sufficient sunlight is needed throughout the growth and development period, such as continuous rain or long-term growth in a semi-shady environment, the stem is not straight and straight, the leaves are soft, drooping, yellowish green, and the disk is small and irregular.

2. Temperature: the suitable temperature for growth is 21: 27 ℃ in daytime and 10: 16 ℃ at night. If the temperature is low, the growth is slow and the flowering time is affected. If the temperature is more than 30 ℃, the stems and leaves are easy to grow and the florescence is shortened.

3. Moisture: the large matrix of ornamental sunflower plants is relatively less, so the growing period should be watered in time, otherwise the leaves are easy to dehydrate and wither. But should not be too wet, the humidity is too large, the basal leaves are easy to yellowing.

4. fertilizer: ornamental sunflower is fertilized once every 20 days during the growing period, usually using 800 times compound fertilizer after water release and then applying alternately, but before flowering, thin phosphorus and potassium fertilizer should be applied 2 or 3 times to facilitate flowering.

5. Cultivation: pot plants do not pick the heart, it is better to have a single flower. The height of tall stalk varieties can be controlled by spraying leaves with 0.25~0.4%B9 solution 20 days after germination. The flower bed can be viewed once and can produce 4-5 flowers.