Eucommia is a dioecious tree. The ratio of male and female plants is about 3:7~5:5. The ratio of male and female plants is about 3:7~5:5, and the age of male and female plants to start flowering and fruiting is generally 5~6 years old, and the fruiting period will be in full swing after 10 years. The Luoyang Forestry Research Institute has tested that the seedlings propagated by grafting method can be fruitful in 3 years after planting, and enter the fruiting period in 5-6 years. Eucommia's economic fruiting age is relatively long, and the fruiting period can reach 50 to 100 years.

The flowering and fruiting of eucommia is greatly influenced by the ground conditions in which the plants are located. The sparser density of unclosed forest stands, scattered trees, forest edge and isolated trees receive more adequate light, the tree development is normal, and the fruiting is good. Plants in denser or already depressed forests have poor light conditions, little space for growth, low fruiting, and seeds that are not full, and generally cannot be used as seedlings. In the existing artificial forest, the fruiting of Duchess is almost not controlled by artificial, over the years, the natural fruiting has gradually formed the phenomenon of big and small years, 1 plant 30 years old tree big year fruiting up to 40 kg, small year fruiting is less than 20 kg, or even no fruit. Therefore, there is a saying that "Duchenne fruits every other year" in each production area. Now the mother tree can be adjusted to take artificial reasonable control, the size of the year or the phenomenon of alternate year results can be basically eliminated.

At present, it is very difficult to distinguish male and female plants from the appearance of eucommia trees before they reach sexual maturity. Into the reproductive period of the male plants of Duchenne, buds rounded full peach-shaped, while the female buds thinner and weaker, oblong conical, this difference is especially obvious in the buds sprouting. In addition, according to some producing areas of the masses summarize the experience of many years, the seedling period from the buds of the sprouting period to identify male and female plants, the accuracy rate of up to 80%. Methods are spring seedlings sprouting, observe the sprouting situation, bud sprouting early more male plants, sprouting late more female plants. The difference between the sprouting time of male and female plants is more obvious in adult trees. In the existing resources of Eucommia, there are many isolated trees growing. Through the investigation in various places, it was found that in the case of no male plants around the isolated female plants, the female plants could still bear fruits normally, and the seeds could germinate normally and grow into new plants. Such as growing in Gansu Province, Kang County, Chengguan town of an isolated female eucommia, its surrounding 10 kilometers within the scope of no other eucommia tree, this 80-year-old isolated eucommia tree, the highest annual seed production of 200 kilograms, the collection of seeds in Luoyang, Henan Province, Nanjing, Jiangsu Province and other places of nursery, the emergence of seedlings neatly, 1 year-old seedling height of more than 1.2 meters. There are also some isolated female plants distributed in new production areas, even only 1 tree in a county, did not affect the results and seedling reproduction. There are two possibilities for this phenomenon: one is the strong pollen dispersal ability, and the other may be the existence of unisexual fruiting.