When making acid soil, acid humus can be buried in the soil, or directly mixed with humus soil to promote soil absorption into acid soil. The pericarp can also be added with water for fermentation, and the prepared solution is added with water for watering. Vinegar can also be diluted by adding clean water, and then sprayed on the surface of the soil, which can be made into acidic soil for several times. Or the ferrous sulfate powder can be mixed with clear water to irrigate the soil for 2 to 3 times a month.
1. Climatic Characteristics of Tianjin
Tianjin is located in the north temperate zone and on the east coast of the mid-latitude Eurasian continent. It belongs to the warm temperate semi-humid monsoon climate and is mainly dominated by the monsoon circulation. However, the influence of the marine climate on Tianjin is relatively obvious.According to the geographical location and climate of Tianjin, the four seasons are distinct, windy and rainless in spring, hot and humid in summer, moderate cold and warm in autumn, cold and dry in winter, so according to the climate characteristics of Tianjin, most of the flowers are more suitable for planting locally.

2. What flowers are suitable for growing in Tianjin
Generally speaking, plants planted in the ground are greatly affected by the regional environment. Is more suitable for planting Chinese roses, Albizzia julibrissin, magnolia denudata, peach blossom, peach, plum, forsythia, golden bell, lilac, redbud, yellow rose, hibiscus, pomegranate, water hyacinth, winter jasmine, red corymb, honeysuckle, Japanese begonia, Wisteria, trumpet creeper, wild rose, Salvia splendens, hollyhock, peony, Petunia, day Lily, flower and leaf vinca, Limonium Dianthus, canna, iris, Coreopsis, etc.

3. What are the city flower and city tree of Tianjin
The city flower of Tianjin is the Chinese rose, and the city tree is the downy ash. Because Tianjin is known as the "hometown of the Chinese rose," and the downy ash is the main tree species of street trees and residential areas in Tianjin, in 1984, after being selected by citizens, recommended by the Municipal Bureau of Parks and Forestry and the Society of Landscape Architecture, and approved by the Standing Committee of the National People's Congress, the Chinese rose and the down ash were designated as the city flower and city tree of Tianjin.
