Can bauhinia flowers spend the winter in the north?
Bauhinia chinensis (scientific name: Bauhinia rubria), a flower in Hong Kong, has its cold-resistant characteristics that are often paid attention to by northern horticulturists. This tropical and subtropical tree can survive at-5℃ to 38℃, but whether it can survive successfully in the north requires comprehensive consideration based on geographical latitude and maintenance techniques. Feasibility analysis of the northern wintering of bauhinia chinensis. Geographical and climatic adaptation range The average annual temperature in the native area of bauhinia chinensis is 20-25℃, and it can naturally wintering in the south of the Qinling Mountains and Huaihe River. Measured data in Beijing (39° north latitude) show that adult plants can tolerate a brief low temperature of-10℃ in the lee and sun, but young plants require special protection. When the main root depth of planted plants reaches 80cm in areas where root cold resistance is key indicators, the soil heat preservation effect is significant. Laboratory data show that roots can remain active when the local temperature is maintained above 5℃, which is a key threshold for successful planting in the north. The micro-environment creation technology of six core measures for the overwintering of bauhinia uses a three-layer protection system: the inner layer is wrapped with a non-woven insulation belt (light transmittance of 75%), the middle layer is erected with windproof bamboo strips, and the outer layer is covered with polyethylene film, which can increase the canopy temperature by 3-5℃. Precise control of water and fertilizer The application of high-potassium slow-release fertilizer (N-P-K=8-12-24) 30 days before winter, combined with EM bacterial agent for root irrigation, can enhance the concentration of cell fluid. Winter watering follows the "three-look" principle: look at the soil (water content <30%), look at the sky (continuous sunny days), and look at the temperature (temperature>5℃). The light management solution adopts movable planting box technology and realizes light management of "going out during the day and returning at night" through a pulley system. During the winter solstice, direct light is guaranteed for 4 hours a day, and full-spectrum fill light is used to extend the light to 10 hours/day. Practical Case of Northern Bauhinia Overwintering Jinan Botanical Garden successfully realized the open-air wintering of bauhinia trees by laying underground geothermal lines (power 15W/m²). Monitoring shows that in extreme weather of-12℃, the rhizosphere temperature still remains above 2℃.
Conclusion: Through scientific cold-proof measures and precise environmental control, the survival rate of bauhinia chinensis in the north can reach more than 85%. It is recommended to adopt the "progressive domestication method", that is, gradually reduce protection every autumn to enhance the cold resistance of plants.