Orange trees can be planted in most areas of Shandong, but the following conditions need to be noted:
1. Temperature: The growth and development of orange trees require a certain temperature range, usually between 12, 5, and 37 ℃. When flower buds differentiate in autumn, it is required that the day and night temperatures be around 20 ℃ and 10 ℃ respectively. Although the winter in Shandong region is cold, if cultivated in a solar greenhouse with warming conditions, as shown in the successful cultivation case of "Red Beauty" citrus in Linyi, orange trees can safely overwinter. However, in some areas near the Yellow River in southwestern Shandong, due to the strong alkalinity, it may not be suitable for planting.
2. Light: Orange trees are shade tolerant tree species, but to achieve high quality and yield, good sunlight is still needed. Areas with an average annual sunshine duration of 1200 to 2200 hours can grow normally. The lighting conditions in Shandong region can basically meet the growth needs of orange trees.
3. Humidity: Orange trees are suitable for planting in tropical and subtropical regions with an annual rainfall of about 1000 millimeters. However, the average annual precipitation in Shandong region is mostly between 550 and 920 millimeters, and the average annual precipitation in the province is about 710 millimeters. During the planting process, attention should be paid to irrigation to maintain the relative moisture content of the soil between 60% and 80%. At the same time, it is necessary to avoid excessive rainfall causing soil water accumulation or high groundwater levels, so as not to affect the growth of orange trees.
4. Soil: Orange trees have a wide adaptability to soil, but it is best to choose soil with a neutral or slightly acidic pH value for cultivation. When the soil layer is deep and the organic matter content is high, the flavor genes of high-quality citrus fruits such as "Red Beauty" can be stimulated and present ideal taste quality. In the Shandong region, except for some areas with severe salinization, the soil conditions in most areas can meet the growth needs of orange trees.
Orange trees can be planted in most areas of Shandong, but attention should be paid to temperature, light, humidity, and soil conditions. During the planting process, it is necessary to strengthen facility construction, improve soil, and learn planting techniques to ensure the healthy growth, high yield, and high quality of orange trees.