What conditions are needed to grow sunflowers?

1. Temperature

Although the sunflower is a tropical plant native to the tropics, it can quickly adapt to the surrounding temperature. It is a heat-loving plant but is also very cold-tolerant. In particular, the seeds have an extremely strong ability to adapt to low temperatures: as long as the ground temperature is above 2°C, the seeds can begin to germinate; the temperature needed for rooting is above 4°C; and the temperature needed for emergence is only 8°C. However, the optimum temperature for germination is around 35°C, and the highest temperature it can withstand is 44°C. In fact, as long as the temperature is not lower than 9°C, sunflowers can grow and develop normally. The more suitable the temperature, the faster they grow and develop.

2. Water

Because the sunflower plant grows relatively tall, with each plant over 1 m, it also needs a lot of water. Its water uptake is about twice that of many crops, but its growth cycle and the rain and heat in the planting area are relatively synchronized, so its demand for water is not very obvious. This is because sunflowers have very different water needs at different stages. From sowing to the bud stage, the water needed is very little, around 2%, because this enhances the drought resistance of the roots and is beneficial for development. From the bud stage to the flowering stage is the period when water is most needed, with water demand reaching more than 40%. If sufficient water is not provided, it may affect yield and reduce the oil content of the planting.

3. Light

Although sunflowers always turn toward the sun, their demand for light is not especially great. They can also grow and develop normally when planted in areas with less sunlight. Sunflowers like sunlight because their leaves, seedlings and flower discs all have strong phototropism. However, if there is sufficient sunlight, it can prevent seedlings from becoming leggy, promote the growth of stems and leaves, increase the seed rate, and also make the seeds plump. It improves yield and quality.

4. Soil

Sunflowers have basically no requirements for soil; they can grow in any soil. This is because they have strong salt tolerance: with a soil salt content of 0.3%, they can still emerge and grow normally, and they are drought-tolerant and waterlogging-tolerant. Experts have tested that after flowering, sunflowers can still flower and bear fruit normally after nearly a month of drought and half a meter of flooding. Although they have no requirements for soil, the degree of dryness and wetness still needs to be controlled. Although it does not affect growth, it will still have a certain impact on sunflower yield.

Sunflowers can not only be used to make sunflower seeds, but are also themselves a medicinal herb that can treat toothache and dispel wind and clear heat. During cultivation, the only thing that needs special attention is water. Each stage has the amount of water it needs, and too much or too little will affect the yield and quality of sunflowers.