Longevity of Paulownia trees
In the streets and courtyards, you can always see the tall and straight figure of paulownia trees. This tree, known as the "king of fast-growing", is not only famous for its astonishing growth rate, but also contains many natural codes in its life cycle and flowering period. Today, we will explore the life trajectory of paulownia trees from germination to bloom through a scientific perspective. Life cycle characteristics of paulownia trees vary in life expectancy among different varieties. Ordinary paulownia varieties generally have a life cycle of 30-40 years, and a unique hollow phenomenon will appear after entering the mature stage. However, special varieties such as the American giant sequoia can survive for more than 3000 years in their native places, and very few ancient trees even span 8,000 years. This difference stems from a combination of genetic characteristics and environmental adaptability. Soil permeability and drainage system, the key factors affecting life span, are the core factors that determine the life span of paulownia. Although this tree species can survive in soil with pH values of 4.5-8.5, sandy loam soil with a soil depth of more than 1.2 meters is most conducive to root development. Areas with an average annual precipitation of 800- 1,200 mm can extend their life cycle by about 15%. The mystery of the flowering period of paulownia trees, the relationship between flowering time and climate is the peak of paulownia flowers from March to April every year, lasting for about 30 days. When the temperature stabilizes above 12℃ in early spring, bell-shaped corolla with a diameter of 4-5 cm open one after another. Purple varieties have the brightest colors when the temperature difference between day and night is 8℃, while white varieties require higher humidity to maintain their flower shape. The flower quantity control technology retains 5-7 main branches through winter pruning, which can increase the number of inflorescences by 40% in the following year. Topdressing application of phosphorus and potassium fertilizers during the bud emergence period, combined with foliar spraying of boron fertilizer, can extend the flowering period of a single flower by 3-5 days, and the overall viewing period can reach 35 days. Light and water management points for paulownia tree planting and maintenance As a strong positive tree species, direct light needs to be guaranteed for 6 hours a day. In the rainy season, a 30-cm-deep drainage ditch needs to be excavated to prevent water accumulation for more than 48 hours. Drip irrigation technology is used during the high temperature period in summer to keep the soil moisture at 60%-70%. Special environmental adaptability experimental data show that paulownia can still grow normally in saline-alkali land with a salt content of less than 0.3%. Organic acids secreted by its roots can improve soil pH, and can reduce the acidity of the surrounding soil by 0.5 units after three years of planting.
From flowers in spring to fruits in autumn, paulownia trees use annual rings to record the mark of time. Mastering its growth laws can not only make the courtyard landscape more hierarchical, but also witness the harmonious coexistence of life and nature. Selecting the right variety and combining scientific maintenance, this oriental sacred tree will surely bloom with more lasting ecological beauty.