Bitter Melon Cultivation Techniques Explained: From Sowing to Field Management

Bitter melon is a high-yielding crop. Its characteristics are a well-developed root system, many lateral roots, a preference for fertilizer but a fear of waterlogging, a love of light but intolerance of heat, and a preference for and tolerance of fertilizer. The fruit of bitter melon tastes sweet and bitter; it is mainly used as a vegetable, and can also be candied. The mature flesh and aril are also edible. Below is an introduction to bitter melon cultivation techniques.

1. Variety Selection

When selecting a bitter melon variety, choose greenish-white or white varieties with strong growth vigor, strong branching ability, heat resistance, disease resistance and high yield, and which suit the local consumption habits, such as Zhongdu Brand Long White Bitter Melon, Qingfeng Bitter Melon, Zhuzhou Long White Bitter Melon, etc. For greenish-white types, use Greenish-White Jade Body Bitter Melon, Jade Green White Bitter Melon, Mingzhu 101, Yushuai, Kanila, etc.; for oily-skin types, use Hybrid Oily-Skin Bitter Melon, Pearl Bitter Melon, etc.

2. Sowing and Raising Seedlings

For winter-spring cultivation, sowing from September to February of the following year is suitable; for autumn cultivation, sowing from July to August is suitable. Bitter melon grown as an intercrop is sown in mid-to-late January. Before sowing, soak the seeds to promote germination; 2-3 days after sowing and emergence, move them into nutrient pots for growing on. Keep the seedling shed temperature at 25-30°C during the day and 15-18°C at night, water less, and provide plenty of light. Starting from the two-true-leaf stage of the seedlings, treat with bitter melon yield-increasing agent once every 3-4 days, for a total of 3 times.

3. Field Planting

According to the growth characteristics of bitter melon, choose a loam soil with ample sunlight, rich organic matter, good drainage and water retention, and a deep soil layer. Avoid continuous cropping, and rotate with non-cucurbit crops for more than 3 years.

Plant bitter melon seedlings on the beds along both sides of the greenhouse and on the bed in the very middle. Dig holes in the middle of the beds and apply a small amount of compound fertilizer. The spacing is 50 cm for pruned plants and 100 cm for unpruned plants. When planting, the roots should not come into direct contact with the compound fertilizer, the cotyledons should be exposed above the ground, and after planting, water to settle the roots.

4. Field Management

1. Cultivation

4-5 days after watering to settle the roots, carry out the first cultivation to a depth of 7-10 cm; two weeks later, carry out the second cultivation to a depth of 3-5 cm. After trellising, no further cultivation is done.

2. Topdressing

During the cultivation of bitter melon, topdressing must be carried out at least 2-3 times. 2-3 days after field planting, on a clear evening, carry out the first topdressing with dilute human waste; the second is applied before flowering to promote fruit set. The third is applied after the second harvest, using a combination of nitrogen, phosphorus and potassium. In addition to soil topdressing, foliar topdressing can also be used to promote vigorous plant growth.

3. Trellising and Guiding Vines

When the seedlings are 30-40 cm tall, insert bamboo in time to guide the vines, using a double-row herringbone trellis. Bitter melon mainly sets fruit on the main vine. When the first female flower appears on the main vine, begin pruning: remove the lateral buds or lateral branches below 1 m on the main vine. In the later growth stage, remove the old yellow leaves at the lower part of the plant, and cut off the old vines without fruit and the thin, weak vines.

5. Timely Harvesting

Generally harvest 15 days after the flowers fade, when the fruit tip begins to shine and the wart-like protrusions on the shoulders are thick and plump. Appropriately shortening the harvest interval can promote the formation of female flowers, which is of great significance for extending the fruiting period and increasing yield. 

For white varieties, harvest as soon as the fruit warts rapidly expand and become clearly protruding and glossy. In the early stage, harvest once every 5-6 days; during the peak fruiting period, once every 2-3 days. It is best to harvest the melons before the sun comes up; those harvested at noon or in the afternoon tend to turn yellow and do not store or transport well.

The above is a brief introduction to bitter melon cultivation techniques. Bitter melon has strong adaptability, grows quickly, sets fruit easily, and is relatively simple to grow; farmers with the right conditions may consider planting it.