The Latest Greenhouse Cucumber Planting Techniques and Method Tutorial

Cucumber, also known as Hu Gua, Ci Gua, Wang Gua, Qing Gua, etc., is an annual creeping or climbing herbaceous plant of the genus Cucumis in the Cucurbitaceae family. It was first brought back to the Central Plains by Zhang Qian on his mission to the Western Regions during the Western Han Dynasty. It is now widely cultivated in temperate and tropical regions, and is commonly grown throughout China, with many regions cultivating it in greenhouses or plastic tunnels. Now let us take a look at greenhouse cucumber planting techniques!

Growing Habits of Cucumber

1. Temperature: Cucumber likes warmth and cannot tolerate cold. The suitable temperature for growth is 10-32°C. Generally, growth is best at 25-32°C during the day and 15-18°C at night. The most suitable soil temperature is 20-25°C, with a minimum of around 15°C. The most suitable day-night temperature difference is 10-15°C. At high temperatures of 35°C, cucumber photosynthesis is poor; at 45°C, high-temperature damage occurs; at low temperatures of -2-0°C, the plants freeze to death. If cold-hardened at low temperatures, they can withstand temperatures as low as 3°C.

2. Light: South China-type varieties are relatively sensitive to short-day conditions, while North China-type varieties are not strict about day length and have become day-neutral plants. Their light saturation point is 55,000 lux, and their light compensation point is 1,500 lux. Most varieties grow well under short-day conditions of 8-11 hours.

3. Water: Cucumber has high yields and high water requirements. The suitable soil moisture is 60-90%. During the seedling stage, water should not be too much, with soil moisture at 60-70%. During the fruiting stage, sufficient water must be supplied, with soil moisture at 80-90%. The suitable relative air humidity for cucumber is 60-90%. If the relative air humidity is too high, disease is very likely to occur, causing reduced yield.

4. Soil: Cucumber likes moisture but cannot tolerate waterlogging, and likes fertilizer but cannot tolerate excessive fertilizer. Fertile soil rich in organic matter should be chosen. It generally prefers soil with a pH between 5.5 and 7.2, but a pH of 6.5 is best.

Sowing Methods for Cucumber

1. Variety selection: For cucumber cultivation, excellent varieties should be selected that tolerate low temperatures in the early stage, tolerate high temperatures in the later stage, and have strong disease resistance, such as Jinyou No. 10 and Bonai No. 3.

2. Seed treatment: Sun-dry the seeds 1-3 days before sowing. After sun-drying, soak the seeds in 55°C warm water for 10-15 minutes, stirring continuously until the water temperature drops to 30-35°C. Rub and wash the seeds repeatedly, rinse off the mucus with clean water, and soak for 3-4 hours. Wrap the soaked seeds in a clean wet cloth and place them at 28-32°C to germinate for 1-2 days. Sow when 70% of the seeds have “whitened”.

3. Soil preparation: For cucumber nutrient soil, garden soil or field soil that has not grown cucurbit vegetables in the past 3-5 years should be mixed with high-quality decomposed organic fertilizer, with organic fertilizer accounting for 30%. Mix the soil and organic fertilizer evenly and sieve. For every 1 cubic meter of soil, add 100 grams of carbendazim to the sieved nutrient soil and mix evenly to make medicated soil.

4. Timely sowing: The sowing period for cucumber is mid-January or late January. Seedlings can be raised in heated greenhouses or energy-saving solar greenhouses. Use nutrient pots 10 cm in diameter and 10 cm high, filled with 8 cm of nutrient soil, and water thoroughly. After the water seeps through, sow 1 germinated seed in each nutrient pot, cover with 1 cm of medicated soil, and cover flat with plastic film to help preserve moisture.

Seedling Stage Management of Cucumber

1. Plastic film mulching: After sowing cucumber, seal with plastic film for 2-3 days. When 2/3 of the seeds have cotyledons emerging from the soil, remove the film promptly. During the seedling stage, water as little as possible to prevent high temperature and high humidity from producing leggy seedlings, and remove straw mats promptly to increase light.

2. Temperature management: Generally, the daytime temperature should be controlled at 25-30°C and should not be too high. The night temperature must be controlled below 15°C, preferably 12-13°C. 7-10 days before planting, harden the seedlings by uncovering greenhouse straw mats early and covering them late, reducing watering, and increasing ventilation amount and time. Keep 20-25°C during the day and 8-10°C at night, with 1-2 short periods of hardening at 5°C.

3. Standards for strong seedlings: Seedling age about 35 days, plant height 15-20 cm, 3 leaves and 1 heart, cotyledons intact, short and thick internodes, dark green and thick leaves, well-developed root system, robust and disease-free.

Field Planting Techniques for Cucumber

1. Land preparation and fertilization: Fertilization should mainly use organic fertilizer, supplemented by chemical fertilizer. The fertilization method should mainly use base fertilizer, supplemented by topdressing. According to the nutritional characteristics of vegetable growth and development, fertilizer requirement patterns, soil nutrient content, and target yield, use an expert fertilization system to determine the fertilizer application rate for vegetables, carry out balanced fertilization, and ensure nutrient balance in the soil. For vegetable plots with medium fertility, generally apply 5,000 kg of high-quality decomposed organic fertilizer, 20 kg of urea, 75 kg of superphosphate, and 30 kg of potassium sulfate per mu. After spreading the base fertilizer, plow deeply 30-40 cm, mix the soil and fertilizer evenly, rake level, and make beds 1.2 m wide, with two 10-15 cm high ridges in each bed, with a ridge spacing of 50 cm.

2. Four-film covering: In early spring, greenhouses use “four-film covering”, namely one layer of greenhouse film, two layers of inner canopy film, and one layer of small arched film over the seedlings. Cover the greenhouse film 20 days before planting to increase soil temperature. Planting can begin when the 10 cm soil temperature in the greenhouse has stably passed 12°C for 3 consecutive days. Hang 2 layers of inner canopy 5-7 days before planting, with a spacing of 20-30 cm. It is best to use 0.012 mm thick polyethylene drip-free plastic film.

3. Timely planting: Spray a fungicide once on the seedbed 1 day before planting. You may choose 50% carbendazim 500 times solution, or 77% copper hydroxide 700 times solution, or 75% chlorothalonil 1000 times solution. Planting should be carried out on a sunny morning. Open furrows on the ridges and water them. When the water seeps to half the furrow, place seedlings at a plant spacing of about 32 cm. After the water seeps in, cover the furrow with soil. This method is called “water-stabilized seedlings”. Plant about 3,500 plants per mu. After planting, cover the bed with a small arched shed.