When is the best time to plant sunflowers?

As a cold-resistant plant, sunflowers are usually sown in late March in the northern regions of mainland China, and sometimes can even be planted in autumn. However, in recent years, the disease problems faced by sunflowers have become increasingly serious, and the pollination efficiency is low, resulting in a decrease in its seed set rate. So when is the best time to plant sunflowers?

When is the best time to plant sunflowers?

Sunflowers are usually planted between late spring and early summer, and the specific sowing time needs to be adjusted according to local climate conditions. The ideal sowing temperature range for sunflowers is 18 to 25 degrees Celsius and when the soil moisture is moderate. In the north, sowing is usually scheduled from April to early May, while in the south, the appropriate sowing time can be advanced to mid-March.

The suitable sowing time for conventional sunflower varieties is between May 10 and 20, while hybrid sunflower varieties are recommended to be sown between May 25 and June 10. As for oil sunflower hybrids, the best sowing period is from May 30 to June 20. Since different varieties have different requirements for sowing time, be sure to refer to the instructions on the seed package to determine the specific sowing time.

The formula for calculating the growing period of sunflower is: the number of days from the sowing date to the local average first frost date plus 7 days. Using this formula, the sowing time can be determined more accurately.

In order to improve the survival rate of seedlings, a late sowing strategy can be adopted. In this way, when the seedlings emerge from the soil, the windy season has passed, reducing the damage caused by wind and sand to the seedlings. At the same time, other plants have already grown by this time, providing more food sources for pests, thereby reducing pest pressure on the sunflower seedlings.

How to plant sunflowers

Seed selection and processing: Select sunflower varieties suitable for the local environment and germinate the seeds before sowing. Soak the seeds in warm water for several hours until they absorb enough water and swell, then take them out and dry them in preparation for sowing.

Land selection: Sunflowers have a well-developed root system and good water tolerance. When selecting land, soil fertility, drainage and irrigation conditions, and land flatness should be considered. Before sowing, the land should be plowed and tidied to loosen the soil, improve germination rate and later growth conditions.

Sowing method: Sow the treated seeds into the soil according to the recommended row spacing and plant spacing (row spacing is about 60 cm, plant spacing is about 30 cm). The sowing depth should be controlled at 2-3 cm, not too deep.

Field management: During the growth period of sunflowers, regular tillage, weeding and fertilization are required to ensure the supply of water and nutrients . Sunflowers have a high demand for fertilizers and should be top-dressed once during intertillage, with nitrogen and phosphorus fertilizers being the main components.

Irrigation: Since sunflower plants are tall and require a lot of water, they should be irrigated at the right time. Irrigation is usually carried out by furrow irrigation, which is carried out three times: the first time is 4-5 days before flowering, or earlier in case of severe drought; the second time is about one week after the first irrigation; and the third time is during the grain filling period.

Light requirements: Sunflowers are light sensitive and require plenty of sunlight. Sufficient sunlight helps the seedlings grow healthily, promotes the development of stems and leaves, ensures normal flowering and pollination, and thus increases yield.

The above is an introduction to the planting time of sunflowers. There are many key points that need to be paid attention to when planting sunflowers to achieve a high yield.