Key Points for Early Spring Greenhouse Cucumber Cultivation

1. Prepare the plot and disinfect the greenhouse.

Begin early greenhouse covering and soil warming; install the greenhouse film 20–30 days before transplanting. For older greenhouses, carry out disinfection by spraying the support posts and the film with trisodium phosphate or sodium hypochlorite, or by fumigating with a fungicidal smoke agent such as chlorothalonil. After the soil has thawed, promptly till the land and apply a sufficient base fertilizer, prioritizing organic fertilizers. Use raised beds and mulch with plastic film.

2. Transplanting seedlings

Transplant seedlings as early as possible, ensuring they are protected from frost damage; maintain a soil temperature of over 12°C at a depth of 10 cm inside the greenhouse, with nighttime temperatures no lower than 5°C. Plant at a moderate density—approximately 4,000 plants per mu—and ensure shallow planting.

3. Greenhouse Management

Temperature Management: In early‑spring cucumber cultivation, the initial stage focuses on insulation and cold protection. During the seedling‑establishment period, avoid ventilation and reinforce nighttime cold‑protection measures; this phase typically lasts about 7 days, during which various strategies should be employed to raise night temperatures and promote rapid establishment. From the end of the seedling‑establishment period to the fruit‑setting stage—approximately 20 days—temperature should be moderately controlled: daytime 20–25°C, nighttime 12–16°C, to prevent excessive vegetative growth. During the peak fruiting period, maintain slightly higher temperatures: daytime 25–30°C, nighttime 16–18°C.

4. Fertilizer and Water Management, and Cultivation

In early spring, soil temperatures are low, so irrigate with a modest amount at transplanting. After the seedlings have established, apply a follow-up watering, followed by shallow cultivation and hardening off. After harvesting the first cucumbers, water again; thereafter, irrigate every five days. Watering should be done on a sunny morning, and after sudden summer downpours, give the plants an additional watering. Following irrigation, ensure timely ventilation to reduce humidity inside the greenhouse.

From transplanting to the harvest of the first fruit, apply supplemental fertilizer 1–2 times; during the peak fruiting period, fertilize every 7–10 days. Alternate between diammonium phosphate and ammonium nitrate, or use a soluble fertilizer applied through irrigation.

5. Vine Training and Pruning

When the cucumber plants reach the fifth node, promptly train them onto a trellis or stake them. Thereafter, wind or tie the vines every 2–3 days, and promptly remove all lateral shoots and tendrils. As the vines approach the greenhouse film, pinch off the growing tip or twist it slightly. Also, promptly remove any diseased or senescent leaves from the lower portion of the plant.