How to Plant Sunflower Seeds: A Detailed Guide to Sowing Time and Methods

The sunflower is an annual herbaceous plant of the genus Helianthus in the family Asteraceae. It is cultivated throughout China. So how do you plant its seeds? When should you sow them? What are the planting methods? According to a sunflower planting base in Shanxi, sunflowers have a relatively strong tolerance to low temperatures at both the seedling and mature stages. The seeds begin to swell and germinate at 2—4℃, can germinate at 4℃, can emerge at 5℃, and 8—10℃ is sufficient to meet the needs of normal emergence. The sowing time is generally from late March to mid-April. Direct sowing or raising seedlings for transplanting are both acceptable. The planting density is 65 cm × 60 cm, with one plant per hole.

How do you plant sunflower seeds? (Potted)

Treatment before sowing:

1. Seed selection before sowing: Select the seeds before sowing and remove shriveled grains and impurities, which can also effectively increase the emergence rate.

2. Sun-drying the seeds before sowing: Before sowing, choose clear weather and spread the seeds out to dry for 2 to 3 days to reduce the moisture content of the grains, increase their temperature, strengthen enzyme activity within the seeds, promote after-ripening, enhance vitality, and improve germination vigor and germination rate. This is beneficial for fast germination and uniform emergence after sowing.

3. Chemical seed dressing: In order to prevent the harm of underground pests and the occurrence of sunflower diseases, and to improve the emergence (and seedling survival) rate of sunflowers, it is best to use 600 g of phorate per mu and evenly mix it with seed fertilizer for soil treatment, or dress the seeds with 0.3 percent abamectin, or dress the seeds with phoxim emulsifiable concentrate, water, and seeds in a ratio of 1:40:500. When dressing the seeds, spray the pesticide while stirring so that the liquid fully soaks the seed coat, then dry the seeds in the shade in time before sowing.

4. Seed soaking and sprouting: Both seed soaking and sprouting can shorten the time for seeds to absorb water and swell in the soil, allow earlier emergence, gain more growth days, promote earlier maturity, and avoid reduced yields from freezing damage after autumn. The specific methods are as follows: Warm water soaking: Soak sunflower seeds in 18℃ warm water. For edible types, soak for 6 to 12 hours; for oil types, soak for 6 to 8 hours. Remove them and dry them until about 70 percent dry, then sow. If sprouting is needed, remove the soaked seeds and place them in a plastic bag, then pile them in a warm room overnight. When the seed coats of some seeds begin to show white and most seeds begin to sprout, they can be sown (they must be sown in a field with good soil moisture, otherwise the sprouts may easily fail).

After the seeds germinate:

1. When the sunflower seeds germinate, push up through the soil surface, and open their cotyledons, they can be transplanted into a large pot. After transplanting, water thoroughly to settle the roots; be sure to water thoroughly. It is recommended to place them indoors in a sunny spot. If they are to be placed under the sun, they should be watered frequently.

2. When about 3 to 4 pairs of true leaves have grown, spray some monopotassium phosphate on the leaves every few days to promote plant growth. Sunflowers need fertilization during growth, and at this time be sure to use thoroughly decomposed organic fertilizer.

What are the planting methods for sunflowers?

1. Land selection: Choose deep soil layers, level land, and supporting irrigation and drainage. A crop rotation period of 3—4 years or more is required, and continuous cropping on the same land is strictly prohibited.

2. Land preparation and fertilization: Prepare the land finely and apply sufficient base fertilizer. Before sowing, there should be no stubble. Apply heavy basal fertilizer and deep fertilizer for deep sowing. In autumn, plow deeply 20—625px, and apply 1000—1500 kg of farmyard manure per mu. On the basis of autumn basal fertilizer application, carry out autumn irrigation at the appropriate time. On the basis of timely rolling and harrowing in winter and spring, level the land and build ridges and shrink the plots before sowing (1—1.5 mu per plot), so that the land is level, the soil is fine, and the soil moisture is uniform. Before sowing, along the edible sunflower rows, deeply apply 10—15 kg of diammonium phosphate, 7—8 kg of potassium fertilizer (potassium chloride or potassium sulfate), or a nitrogen-phosphorus-potassium compound fertilizer.

3. Before sowing, the seeds should be sun-dried for 2—3 days. Use 150 mL of 40% zinc phoxim, mix with 5—7.5 kg of water, and dress 25—30 kg of seeds to prevent underground pests. Soak the seeds for 6 hours in a 500-fold solution of carbendazim, or dress the seeds with dimethachlon or thiophanate-methyl, etc. The dosage is 0.5—0.6% of the seed weight, in order to prevent sclerotinia.

4. Use hole sowing or drill opening with a seed drill for manual fixed-distance spot sowing. On clay soil, sow 82.5px deep; on sandy loam and sandy soil, sowing depth can reach 4—150px. The sowing period for sunflowers is generally earlier for spring sowing, and the sowing method is mainly manual hole sowing. In hole sowing, seeds can be placed according to the required plant spacing, with a sowing depth of about 5 cm. Generally, for hole sowing, the seeding rate is 1—1.5 kg per mu, with 4—5 seeds per hole. Use wide and narrow row sowing, with a large row spacing of 100 cm, a small row spacing of 50 cm, and a plant spacing of 60 cm, leaving about 1400 plants per mu.