When to plant sunflowers? A full analysis of the best sowing time
Sunflowers have a short growth cycle and are not afraid of high temperatures. To ensure good flowering, we generally choose to sow from March to April, which is the golden time for planting sunflowers. The optimal temperature for sowing sunflowers is between 18 and 25 degrees, and they can bloom about 50 to 80 days after planting.
Sunflowers, which could clearly rely on their looks but insist on relying on their strength, must be very popular with everyone. In fact, the method of growing sunflowers is very simple, and beginners can easily grow them at home.
When to sow sunflowers? An introduction to sunflower sowing time
Sunflowers can be planted in all four seasons, usually mainly in summer and winter, and the flowering period can last more than two weeks. Besides looking like the sun, their bright and elegant flowers are very suitable for ornamental display, and the seeds have even greater economic value. They can not only be made into the popular sunflower seeds, but also be pressed into low-cholesterol premium edible sunflower oil. Now let us take a look at when to sow sunflowers!
Sunflower sowing time
The sowing time for sunflowers is March to April, the suitable temperature for sowing is 18 to 25°C, and they sprout about 5 to 7 days after sowing. The basic principle for choosing the sowing period is to sow appropriately early or late according to the patterns of salinization and alkalization, so that the seedlings avoid salt and alkali damage. Spring or summer sowing is carried out according to the growth period of the variety. Adjust the sowing period according to the patterns of disease occurrence so that it avoids the season when diseases are frequent. Adjust the sowing period according to growth characteristics so that the flowering and grain-filling period avoids high temperatures above 28°C. The sowing method is dibbling, covering with about 1 cm of soil, and flowering occurs about 50 to 80 days after sowing, with slight differences in each aspect depending on the variety.
Sunflower growing environment
1. Temperature: Sunflowers are a temperature-loving and cold-tolerant crop, with strong adaptability to temperature. The seeds have very strong low-temperature tolerance. When the soil temperature is stable above 2°C, the seeds begin to germinate; at 4 to 5°C they can sprout and take root; when the soil temperature reaches 8 to 10°C, it can meet the needs of seed germination and emergence. Throughout the entire growth process, sunflowers can grow normally as long as the temperature is not lower than 10°C.
2. Water: Sunflowers are a crop that consumes a relatively large amount of water. The plants are tall, with many dense leaves, and their water absorption is 1.74 times that of corn. However, because their growth and development are mostly synchronized with local rainfall and heat, the contradiction between water supply and demand is not prominent, and the water requirements differ greatly at different growth stages. From sowing to budding, they need little water; from budding to flowering is the peak water-demand period; and from flowering to maturity, the water requirement is also relatively high.
3. Light: Sunflowers are a short-day crop and are not very sensitive to daylength. They like ample sunlight, and their seedlings, leaves, and flower disks all have strong phototropism. With sufficient sunlight, the seedlings are robust and can be prevented from becoming leggy. Sufficient sunlight in the middle growth stage can promote vigorous stem and leaf growth, normal flowering and pollination, and increase the seed-setting rate. Sufficient sunlight in the late growth stage makes the seeds plump and full.
4. Soil: Sunflowers have low soil requirements and can grow in all types of soil, from fertile soil to dry land, poor soil, and saline-alkali land. They not only have strong saline-alkali tolerance, but also have salt-absorbing properties. At the same time, sunflowers have well-developed root systems and strong drought resistance. Moreover, the roots and stems of sunflowers have well-developed aerenchyma, making them very tolerant of waterlogging.
Sunflower growth cycle
1. Seedling stage: The period from emergence to budding in sunflowers is called the seedling stage, generally requiring 35 to 50 days, or 28 to 35 days for summer sowing. This period is the stage of leaf and flower primordium formation and floret differentiation. The seedling stage of sunflowers is the stage with the strongest drought resistance. Aboveground growth is slow, while underground root growth is faster, quickly forming a strong root system.
2. Budding stage: From budding to flowering, sunflowers generally need about 20 days. This is a period when vegetative growth and reproductive growth proceed together, and it is also the most vigorous stage in their life. During this period, they need the most fertilizer and water, accounting for about 40 to 50% of the total fertilizer and water demand. If the need for water and fertilizer cannot be met in time, yield will be seriously affected.
3. Flowering stage: For a sunflower head, the period from the opening of the ray florets to the completion of the opening of the tubular florets generally takes 6 to 9 days. From the second day to the fifth day is the full-bloom stage. They mostly open from 4 to 6 in the morning, and pollination occurs the next morning. Unpollinated stigmas can remain viable for 7 to 10 days, but the seed-setting rate from self-pollination is only about 3%, while the seed-setting rate from cross-pollination is high.
4. Maturity stage: The maturity stage of sunflowers refers to the period from flowering to maturity, 25 to 55 days for spring sowing and 25 to 40 days for summer sowing, with differences among varieties. About 15 days after flowering and pollination is the seed formation stage. The maturity stage of sunflowers requires clear weather, a relatively large temperature difference between day and night, and suitable soil moisture.
When is the best time to plant sunflowers? Sunflower planting time and methods
When it comes to sunflowers, I believe everyone is familiar with them. Sunflowers are annual herbaceous plants of the genus Helianthus in the Asteraceae family. They not only have high ornamental value, but are also an important oil crop in our country, with high planting value, and have attracted many farmers to grow them. So, when is the best time to plant sunflowers? How should they be planted? Below is an introduction to the planting time and methods of sunflowers. Let us take a look.
Image: Sunflower
1. Sunflower planting time
The sowing time for sunflowers is March to April, the suitable temperature for sowing is 18 to 25°C, and they sprout about 5 to 7 days after sowing. The basic principle for choosing the sowing period is to sow appropriately early or late according to the patterns of salinization and alkalization, so that the seedlings avoid salt and alkali damage. Spring or summer sowing is carried out according to the growth period of the variety. Adjust the sowing period according to the patterns of disease occurrence so that it avoids the season when diseases are frequent. Adjust the sowing period according to growth characteristics so that the flowering and grain-filling period avoids high temperatures above 28°C. The sowing method is dibbling, covering with about 1 cm of soil, and flowering occurs about 50 to 80 days after sowing, with slight differences in each aspect depending on the variety.
Image: Sunflower
2. Sunflower planting methods
1. Land selection and preparation:For sunflower cultivation, choose a plot with level land, medium fertility, convenient irrigation and drainage, and relatively low soil stickiness, and it should not be continuously cropped. They reproduce by seed, and peat soil is suitable for sowing. Before sowing, mix the seeds with new high lipid film, which can repel underground pests, isolate viral infection, and improve the seed germination rate.
2. Timely sowing:The sowing time for sunflowers is generally March to April, the suitable temperature for sowing is 18 to 25°C, and they usually sprout about 5 to 7 days after sowing. The basic principle for choosing the sowing period is to sow appropriately early or late according to the patterns of salinization and alkalization, so that the seedlings avoid salt and alkali damage. Spring or summer sowing is carried out according to the growth period of the variety.
3. Field inspection and replanting:Sunflowers are a dicotyledonous crop, and it is relatively difficult for them to push through the soil and emerge. In addition, poor land preparation, poor sowing quality, surface soil crusting after rain following sowing, or damage by diseases, insects, rodents, birds, and other pests can all easily cause missing plants and broken rows. To ensure full emergence after sowing, it is necessary to inspect field by field and row by row during the emergence period, and replant in time where plants are missing in large patches or rows.
4. Thinning and final singling:In sunflower cultivation, thinning should be done early to prevent seedlings from crowding each other, affecting the cultivation of strong seedlings and even later yield. As for saline-alkali land and plots with severe pest damage, the time for final singling can be appropriately delayed. At the same time, sunflowers should also be singled early, which is beneficial for cultivating strong seedlings and for flower disk development. Final singling should be carried out when there are 2 pairs of true leaves.
Image: Sunflower
5. Cultivation and weeding:Sunflowers are generally cultivated 2 to 3 times to weed and loosen the soil, break up crusting, conserve water, reduce evaporation, and reduce salt and alkali damage. The first cultivation is carried out at the 1 to 2 pairs of true leaves stage together with thinning and final singling, the second cultivation is carried out 1 week after final singling, and the third cultivation is completed before row closure together with ditching, hilling, and fertilizing.
6. Ditching and topdressing:Sunflowers relatively like fertilizer. Ditching and topdressing are usually carried out at the third cultivation, mainly with nitrogen and phosphorus fertilizer, applying 5 kg of diammonium phosphate and 10 kg of urea per mu, mixed evenly and applied into the soil. Ditching and hilling can effectively ensure the growth and development of secondary roots, prevent lodging, and reduce basal branching below the cotyledon node.
7. Timely irrigation:Sunflower irrigation uses the furrow irrigation method. Generally, for varieties with a plant height of 1.5 m, the first watering should be carried out at the bud stage, the second at the early flowering stage, and the third at the grain-filling stage. For varieties with a plant height of about 2 m, the first watering is carried out 4 to 5 days before flowering (if drought is severe, irrigation is earlier), the second 6 to 7 days after the first watering, and the third at the grain-filling stage.
8. Pollination management:Sunflowers have a low seed-setting rate from self-pollination and a high seed-setting rate from cross-pollination. During cultivation, artificial supplementary pollination should be carried out in time, using methods such as matching flower disks, powder puffs, and cotton gloves to transfer pollen, or collecting pollen from the male parent and gently applying it to the stigma of the female parent with a small brush. Pollination should be carried out 3 to 4 times during the full-bloom stage.
[Editor's concluding remarks]Sunflowers are cultivated in all parts of our country and have high cultivation value. The above has introduced the planting time and methods of sunflowers for everyone, and I hope it will be helpful to you!