When do trees bloom?

Paulownia trees, also known as white paulownia, big fruit paulownia, paulownia trees, etc., belong to the deciduous tree of Scrophulariaceae, with fast growth, wide distribution, good material and many uses. it is not only suitable for afforestation and afforestation on all sides, but also suitable for the implementation of farmland forest network and paulownia intercropping in the vast areas of North China and Central Plains. Let's take a look at when paulownia trees will bloom.

When does the paulownia tree bloom?

Paulownia trees usually bloom from March to April, and the flowering period lasts about one month. 3-5 paulownia flowers form small Cymes with total pedicels or none, but most of them form large inflorescences due to the shedding of winter leaf-like involucre and bracts. The lateral branches of inflorescence branches vary in length, making the inflorescences paniculate, pyramidal or cylindrical. Corolla large, purple or white, funnel-shaped bell-shaped to tubular funnel-shaped, there are two longitudinal pleats in the abdomen (only white paulownia has no obvious longitudinal pleats), there are often dark purple spots on the inside, yellow at the longitudinal fold uplift.

Growth habits of paulownia trees

Paulownia is a positive tree species, which is most suitable for growing in sandy loam or gravel soil with good drainage, deep soil layer and good aeration. It likes moist and fertile soil, pH6~8 is better, and has a tendency to selectively absorb elements such as magnesium, calcium and strontium. Paulownia has strong adaptability, generally can grow in acidic or alkaline soil, or in barren low mountains, hills or plains, but avoid stagnant water. It also has a wide range of adaptation to temperature. It can withstand the low temperature of-20 ℃ ~ 25 ℃ in the north, and can grow from the south of Liaoning, North China, Central China, East China, South China, Southwest to Northwest in Northeast China, and there are species adapted to the local ecological environment.

Variety classification of paulownia trees

1. Southern paulownia: the tree of southern paulownia is paniculate or broadly conical, the leaf center is round, the back of the leaf is densely dendritic hairy and sticky glandular hairy, the panicle branch is broad, the fruit is oval, fruiting. It is distributed from Zhejiang and Fujian to northern Guangdong, Hunan and the mountainous areas at the junction of Sichuan, Hubei, Hunan and Guizhou provinces. It is wild in the hills and mountains of Zhejiang, Fujian and eastern Sichuan.

2. White paulownia: the trunk of white paulownia is straight and tall, the leaves are long ovate-shaped, the back is long-stalked dendritic hairs, the inflorescence branches are narrow, cylindrical or narrow paniculate, and the Corolla is white or light purple. Paulownia is the most widely distributed species in the south, spread to the south of the Yangtze River, from Taiwan in the east, to Gaoligong Mountain in the westernmost part of Yunnan in the west, and to the north of Vietnam and Laos in the south.

3. Catalpa leaf paulownia: the trunk of catalpa leaf paulownia is straight, the branching angle is small, the leaf is long, ovate, heart-shaped, nearly twice as long as wide, and the back is dense with short-stalked dendritic hairs. Inflorescence branches paniculate or narrowly paniculate. It is distributed from Jiaodong Peninsula in the east, southward to the mountains of western Henan through Taihang Mountains and Zhongtiao Mountains, westward to the lower reaches of Luohe River in Shaanxi Province, to Beijing in the north and to the Huaihe River Basin in the south.

4. Lankao paulownia: the trunk of Lankao paulownia is intermittent dry type, with ovate heart-shaped leaves, entire or sometimes angular base, sessile dendritic hairs on the back, and glabrous above. The inflorescence branches are paniculate and the fruit is oval-shaped, which often bear little fruit in North China, but increase significantly in the Yangtze River basin, distributed from the middle and lower reaches of the Yangtze River to the middle and lower reaches of the Yellow River.

5. Paulownia: the crown of paulownia is umbrella-shaped or conical, mature leaves ovoid-heart-shaped, entire or microwave-shaped, the back of leaves is yellow. Inflorescence branches broadly paniculate, flowers purple or white Corolla base suddenly dilated bell-shaped, capsule ovoid. Distributed in the southern slope of Shennongjia, Yichang and western Hunan, as well as the mountains of Sichuan, Guizhou and Yunnan, most of them are wild.

6. Taiwan paulownia: the crown of Taiwan paulownia is umbrella-shaped, the leaves are ovoid or broadly ovate-shaped, the inflorescence branches are broadly paniculate, the Cymes have no peduncle, and the capsule is ovoid. Fruit shell thin shell. It is distributed in the southeastern provinces south of the Yangtze River, including Zhejiang, Fujian, Taiwan, Guangdong, Guangxi, Jiangxi, Hunan, as well as southwestern Hubei and southeastern Sichuan.

7. Paulownia tomentosa: the crown of paulownia is umbrella-shaped, the leaves are wide ovoid-heart-shaped, the inflorescence branches are broadly conical, the Cymes are nearly as long as the pedicel, the fruit is ovoid, the fruit shell is thin and shelly. Paulownia is the most widely distributed species in the north. It is cultivated in the vast areas from the middle and lower reaches of the Yangtze River to southern Liaoning, Beijing, Taiyuan and Tianshui, and mostly introduced in the south of the Yangtze River.

8. Light paulownia: light paulownia is a variety of paulownia of Scrophulariaceae. The main difference from paulownia is that the mature leaves are glabrous or extremely sparse, and the base is round to shallow heart-shaped. Distributed in Shaanxi, Gansu, Shanxi, Hebei, Henan, Shandong, Hubei, northern Sichuan, cultivated or wild, up to 1700 meters above sea level.