Jacaranda. 
Goldenrod bell tree.
Purple bell tree.
Bauhinia. South China, Southwest China and other southern regions can be planted flower-viewing street trees, such as jacaranda, golden-flowered bell tree, purple flower bell tree, Bauhinia, etc., the flower color is gorgeous, the street scene is beautiful, which makes people envious. However, most of these trees belong to the tropics, and even if they can be planted in winter when the temperature is below 5 degrees Celsius, it is difficult to produce a few flowers. The vast majority of northern cities have winter temperatures below 5 degrees Celsius.
Cherry blossoms
Some people say that cherry blossoms, begonias, etc. can also be cultivated into the best street trees, but the implementation of road trees not only requires trees to be tall and straight, good shade, but also less pests and diseases, strong adaptability, wind resistance, pollution resistance, salt and alkali resistance, and long tree age.
Isn't there a street tree in the northern city where you can enjoy the flowers? The garden trees to be used in northern cities should be excavated from native tree species, which is a long-term solution, rather than blindly pursuing the introduction and domestication of cold-tolerant southern tree species, and even building greenhouses to prevent freezing.
Hubei Bauhinia (Giant Bauhinia).
Hubei Bauhinia specimen distribution heat map Hubei Bauhinia (cercis glabra) is a tree height of up to 16 meters, the age of the tree is more than 150 years old Leguminaceae Bauhinia ornamental tree, the distribution range is very wide, most northern cities can be planted, is a northern flowering street tree "good seedling". However, the native species of Bauhinia Hubei is lighter in color (pale pink), less in flowering, shorter in flowering period (about two weeks), fast in growth, and not enough in the canopy, so the landscape expression is not very ideal.
Sijichun No. 1 Bauhinia Tree is a Bauhinia tree (cercis glabra) selected and bred from Hubei Bauhinia Bauhinia (Cerabis'sijichun-1'It is a new and excellent variety of flower-viewing street trees suitable for planting in northern cities, with bright flower color (purple-red), large amount of flowers, long flowering period (about four weeks), first flowering and then leaves, medium growth rate, canopy development, better shading effect, and both ornamental and ecological value.
The 'Sijichun No. 1' Bauhinia Tree planted in Shijiazhuang Road Greening Hebei Province has a low temperature of about minus 10-18 degrees Celsius in winter, the temperature in the road green belt will be lower than that in the park, the wind will be stronger, and the soil is usually drier, barren and salinity. As a result, the species that can be planted in the green belt of the road can be planted in almost all green spaces in the area.
After nearly eight years of planting experiments, the 'Sijichun No. 1' redbud tree planted in Shijiazhuang road greening can not only safely overwinter in Shijiazhuang's road green belt, but also present a more ideal flower-viewing effect, which is a rare cold-resistant flower-bearing street tree variety that can also be planted in northern cities, which is worthy of vigorous promotion and application.
In addition to its strong resistance to stress, the 'Sijichun No. 1' redbud tree planted in Shijiazhuang road greening also has a great advantage that it is clean and clean, and there is basically no problem of pests and diseases, flowing gum and flowers and leaves and fruits falling to pollute the road surface and roof. You can enjoy flowers in spring, shade in summer, leaves and fruits in autumn, and leaves in winter.
With the passage of time, these 'Sijichun No. 1' Bauhinia trees planted as street trees in Shijiazhuang will have thicker trunks and side branches, a large and dense crown, and the flowering effect will become better and better. The redbud street scene created by it may be comparable to the jacaranda and purple bell trees in the south in terms of visual impact and aesthetic dreaminess.
The 'Sijichun No. 1' redbud tree planted in the greening of the road in Ruzhou, Henan Province The above article is in the Chinese Garden Magazine, the author of "Chinese Garden".