随着社会进步和人们生活水平的提高,花卉在改善生态环境和城市绿化美化中的作用越来越重要了。由于长春市地处北纬43°54’,属大陆季风性气候,无霜期短,露地花卉生长时期及观赏时期受到了环境条件的制约,延长花卉的观赏时期,提高观赏价值成为人们关注的问题。如何能达到这一效果 With the progress of society and the improvement of people’s living standards, the role of flowers in improving the ecological environment and urban greening and beautifying is more and more important. Since Changchun City is located at latitude 43 ° 54 ’north latitude, it belongs to the mainland’s monsoon climate, has a short frost-free period, is restricted by the environmental conditions during the growth and ornamental period of the open-air flowers. It is a problem that people pay attention to extend the viewing period of flowers and improve the ornamental value. How to achieve this effect?