Detailed Explanation of Key Points on Forsythia Cultivation Techniques

Forsythia cultivation is as follows:

1. Site selection and land preparation: Choose a sunny plot with fertile, loose-textured, well-drained sandy loam soil. Plow in autumn to a depth of 20-25 cm. While preparing the land, apply base fertilizer at 2000-2500 kg of barnyard manure per mu, then harrow fine and level. For direct seeding plots, use a plant-to-row spacing of 130 cm × 200 cm, with holes 30-40 cm deep and 30-40 cm in diameter; for seedling beds, make flat beds 1 m wide, with length depending on the terrain.

2. Propagation methods: Mainly seed propagation and cutting propagation, but layering and division can also be used.

(1) Seed propagation and direct seeding: In the south, sow in early to mid-March; in the north, sow in early April. In the prepared holes, dig a small pit about 3 cm deep, select mature, plump, disease-free seeds, sow 5-10 seeds per pit, cover with soil and press lightly so the seeds are in close contact with the soil. Generally, they bloom and bear fruit after 3-4 years.

Seedling raising and transplanting: On a level, finely harrowed seedling bed, open furrows 1 cm deep at a row spacing of 20 cm, mix the seeds with fine sand and scatter them evenly into the furrows, cover with soil and press lightly, using 2 kg of seeds per mu. Spring-sown seeds emerge in about half a month. When seedlings are 5 cm tall, thin them to a set stand; when 10 cm tall, loosen the soil and weed, and apply 10 kg of urea per mu as a top dressing, applying it with irrigation water to promote seedling growth. Transplant in autumn of the same year or before bud break in spring of the following year. Use a plant-to-row spacing of 120 cm × 150 cm, with holes 30 cm in diameter. Apply 5 kg of mixed manure, mix thoroughly with soil, plant 2-3 seedlings, fill soil to half the hole, lift the seedlings slightly so the roots spread out, then fill the rest with soil and firm it. If the soil is dry, water after transplanting, and after the water seeps down, earth up to conserve moisture.

(2) Cutting propagation: On cloudy and rainy days in summer, cut the middle and upper parts of 1-2-year-old tender branches into 30 cm-long cuttings. On the seedling bed, at a plant-to-row spacing of 5 cm × 30 cm, open furrows 20 cm deep, place the cuttings obliquely in the furrows, then cover with soil and press firmly. Keep the bed moist; they will take root and survive in the same year, and can be transplanted before bud break in spring of the following year.

3. Field management: During the seedling stage of seed propagation, when seedlings are 20 cm tall, weed, loosen the soil and thin the seedlings. When thinning, leave 2 plants per hole and water timely. When seedlings are 30-40 cm tall, apply diluted human and animal urine once to promote growth. When the main trunk is 70-80 cm tall, cut off the top shoot to encourage more lateral branches and cultivate them into main branches. Thereafter, select and retain 3-4 strong branches on the main branches to cultivate into secondary main branches, and let out lateral branches. Through shaping and pruning, form a natural open-center tree shape with a low, short crown, hollow inside and rounded outside, good ventilation and light penetration, sparse small branches, and early fruiting. At any time, prune away thin and weak branches, water sprouts, and diseased and pest-infested branches. During the fruiting period, apply farmyard manure and phosphorus and potassium fertilizers to promote early fruit set and ripening.