Time and method of planting bitter melon in the open air

Bitter melon is widely grown throughout our country. However, many growers encounter problems such as slow germination, low yield and poor quality when cultivating bitter melon, resulting in low planting efficiency. Now let’s learn the time and method of planting bitter melon in the open air.

1. Sowing at the right time

Planting too early may result in slow or no emergence. The most suitable temperature for bitter melon germination is 30-35℃. Germination is slow when the temperature is below 20℃, germination is difficult when the temperature is below 13℃, and the seeds will not germinate when the temperature is below 10℃. When planting bitter melon in spring, you can sow when the average daily temperature is stable above 15℃. The sowing time varies in different regions. It is generally in mid-to-late March in South China and Southwest China, in mid-April in Central China, and in late April or early May in Northeast China. When sowing, it is recommended to use film to build a small arch shed and cover it with ground film or straw to retain moisture to speed up emergence of seedlings.

2. Germination of seeds before sowing

Bitter melon seeds have thick seed coats and germinate slowly under natural conditions. Germination can speed up germination, which is beneficial for uniform and complete seedlings. Put the seeds in hot water at about 55℃, stirring constantly. Stop stirring when the water temperature drops to 30℃ and soak for 8 hours. After soaking, wash the seeds three times with clean water, wrap them with wet gauze and place them in a place around 30℃, keeping the gauze moist. Generally, most of the seeds will turn white in 3 to 4 days and can be sown. Before large-scale planting, it is recommended to disinfect seeds to reduce the risk of disease.

3. Cultivate strong seedlings

During the germination process, seeds can be sown when 70% of them turn white. Using nutrient pots or paper cups to grow seedlings is conducive to cultivating seedlings with thick stems and well-developed root systems. Prepare nutrient soil that is rich in organic matter and loose. Mix garden soil and decomposed farmyard manure evenly, put it into nutrient pots or paper boxes, put one seed in each pot, cover the soil to a depth of 2 cm, water the soil thoroughly, and water it every 3 days after the seeds germinate. The seedlings can be transplanted when they have 4 to 5 true leaves.

4. Site selection and reasonable density planting

Bitter melon is not very demanding on the soil, but it should not be planted in low-lying areas or areas with high groundwater levels, nor can it be planted in shady areas. Choose a plot with deep soil, loose soil, convenient irrigation and drainage, and rich organic matter content. Deeply plow the soil, rake it flat and fine, dig planting holes with a row spacing of 80 cm and a plant spacing of 40 cm, and apply fully decomposed farmyard manure and a small amount of compound fertilizer as base fertilizer. After transplanting the seedlings, if the soil is dry, you can water them.

5. Water less during the seedling stage, and water frequently after the melons are ripe.

Bitter melon likes moisture, but it is not easy to water it too much before it blooms and bears fruit, so as not to cause the seedlings to grow too tall. Proper soil dryness helps control growth and promote root growth. The principle of watering bitter melon is: water less during the seedling stage, and no watering is required if the soil is not dry. Watering should be done every 7 to 10 days; keep the soil moist after the bitter melon sets fruit, and water frequently with small amounts of water.

6. Apply less fertilizer in the seedling stage and more topdressing in the fruiting stage

Bitter melon likes fertilizer, but it is not advisable to apply too much fertilizer during the seedling stage to avoid causing the plant to grow too tall. During the seedling stage, you can water the plants 1 to 2 times with decomposed thin manure water or apply a small amount of urea. Bitter melon requires a large amount of fertilizer during the flowering and fruit-bearing period. Insufficient nutrients will cause premature aging of the plant, affecting yield and quality. After flowering, apply 40 kg of triple compound fertilizer per mu to promote flowering and fruiting and fruit enlargement. After bitter melon blooms and bears fruit, it has a higher demand for phosphorus and potassium. You can spray 0.3% potassium dihydrogen phosphate foliar fertilizer once every 7 to 10 days, and spray 2 to 3 times in a row.

7. Vine pruning

Bitter melon needs to be cultivated on a trellis. When the seedlings grow to 50 cm long, the vines can be led onto the trellis and the vines can be lightly tied with ropes every 30 cm. Bitter melon will grow many side vines during its growth process. You can remove the side branches below 50 cm from the ground as well as the dense, old, and diseased branches and leaves. This will increase ventilation and light transmission in the field, reduce nutrient waste, and help the bitter melon to bloom and bear more fruits.

To sum up, if you want to grow high-yield, high-quality bitter melon, you must do a good job in every aspect of field management, so that the probability of achieving high yield will increase.