When to Plant Watermelons
Mastering the timing of watermelon planting is the first key step to a bountiful harvest. As a summer refreshment delicacy, watermelons require a complete growth cycle from sowing to harvesting, with significant differences in planting seasons for different varieties and regions. This article will systematically analyze the golden period for sowing watermelons and the supporting cultivation techniques to help you grow premium, sweet, and juicy watermelons.
Three Key Elements of Watermelon Planting Time
1. Variety Characteristics Determine the Planting Cycle
Early-maturing varieties like Jingxin No.1 are recommended to be sown in mid-March, with a growth period of about 95 days; mid to late-maturing varieties like Xinong No.8 should be cultivated in late April and require 110 days to mature. The popular yellow-fleshed watermelons are usually planted in early May to meet special market demands.
2. Regional Climate Affects the Sowing Node
In the Yangtze River Valley, it is recommended to sow around Qingming (Tomb Sweeping Day), and in the North China region, it is suitable to cultivate during Guyu (Grain Rain). A stable ground temperature of 15°C is the baseline for outdoor planting, and in areas with frequent cold spells, it can be postponed by 7-10 days. In the highlands of Yunnan and Guizhou, due to the large temperature difference between day and night, staggered-season planting can be implemented.
3. Facility Cultivation Extends the Production Period
Greenhouse planting with temperature control can advance the sowing period to February, and with the multi-layer mulching technique, it can achieve multi-cropping throughout the year. Smart greenhouses can accurately control parameters like humidity and light, breaking through traditional seasonal limitations.
Five Key Technologies for Watermelon Sowing
Seed Pretreatment Process
Soak seeds in 55°C warm water for 12 hours to break dormancy, then disinfect with a 0.1% potassium permanganate solution. The new shell-breaking germination method can increase the germination rate to 95%. The specific operation is: gently grind the seed scar with sandpaper and place it in a 28°C incubator for 48 hours to expose the white tip.
Scientific Sowing Regulations
Make trenches with a row spacing of 1.8 meters and maintain a plant spacing of 0.5 meters. The sowing depth should be 2-3 cm, with the芽 tip facing up, and gently press the soil after covering to ensure the seed sticks to the soil. It is recommended to use the double-row staggered sowing method to increase photosynthetic efficiency by 15%.
Key Points for Full Cycle Management
During the vine extension period, maintain a daytime temperature of 25-30°C and a nighttime temperature above 18°C. Apply high-potassium water-soluble fertilizer during the fruit-setting period and maintain soil moisture at 70%. Use the three-vine pruning method, and leaving fruit on the second female flower of the main vine can increase sweetness by 1-2 degrees. Controlling water 10 days before harvesting significantly improves sugar content.
By accurately grasping the watermelon planting time window and combining modern cultivation techniques, the yield per mu can be increased by over 30%. It is recommended to establish a planting calendar based on local climate characteristics, regularly test soil EC values, use IoT devices to monitor the growing environment, and achieve scientific and standardized production.