Growing Eucommia ulmoides Oliv. plants at a nursery in Saint Petersburg

In Chinese medicine Eucommia ulmoides Oliv. has been used for over 1000 years. Galenic preparations obtained from the bark of this plant are known to have a strong hypotensive effect; they belong to the group of antispasmodic drugs, do not cause any side effects, and are low toxic. In natural conditions, Eucommia ulmoides grows in China, mainly in the middle reaches of the Yangtze River. Being frost-resistant, it compares favorably with most of subtropical plants. Therefore, when grown in St. Petersburg, special attention should be paid to its ability to withstand frost. The aim of this work was to assess the differences in the parameters of seeds, germination, and the growth of Eucommia ulmoides seedlings in the nursery of the botanical garden of St. Petersburg State Forest Technical University from seeds of various origins: natural habitat and different places of introduction. The state of deep dormancy is inherent in the seeds of Eucommia ulmoides. The seeds that were subjected to cold stratification in 2018 had higher germination rates than those sown in a greenhouse without stratification. They began to germinate from late May to mid-July, and the seed germination period may last until the spring of next year (2019). Sown in a hothouse, nonstratified seeds began to germinate from late September 2018 to mid-January 2019. The germination rate of seeds differed significantly depending on the places of their collection. The best sowing qualities are possessed by seeds harvested in the Botanical Garden of Sukhum, harvest of 2017, and Kropotkin, harvest of 2019 (average germination rate 31.4–40.7 %). Seeds from China and Canada did not germinate; seeds from Vietnam and the Sochi arboretum had a very low germination capacity. Two-year-old Eucommia ulmoides seedlings grown in the hothouse had healthy green leaves and, depending on the origin of the seeds, their height ranged from 53.3 to 67.5 cm, and the average diameter of the root collar was between 5.7 and 7.5 cm. Two-year-old seedlings grown from the seeds of the Sukhumi Botanical Gardens in the open field in the nursery of the botanical garden of St. Petersburg State Forest Technical University were 14.9 cm in height and their the root collar diameter was 2.9 cm. As a result of the studies, it has been found that for the introduction of Eucommia in the conditions of St. Petersburg, it is necessary to pay great attention to the geographical origin of the seeds and methods for their pre-sowing preparation.