Short communication: Propagation and cultivation of Sakura (Prunus sargentii) in the Main Botanic Gardens, Russian Academy of Sciences
Volume 5 Number 2 - July 2008
For the Japanese, Sakura is a sacred plant and when it blossoms, it is a delight to behold. In the spring over 100,000 tourists come from every corner of the world to admire the famous cherry blossom. As Japan is made up of a series of islands with different climatic conditions, the flowering period for Sakura can last for two full months. The first flower buds begin to open in the middle of March on the Southern part of Kyushu and the last buds are finished by the middle of May on Hokkaido Island. Sakura is not a defined plant, nor even a particular species. It is an image. In Japan several species of endemic cherries, such as Prunus jamasakura, P. sargentii, P. incisa, P. vericunda, P. lannesiana var. speciosa, P. maximowiczii, P. nipponica, P. pendula f. ascendens, P. apetala, P. buergeriana, and P. grayana, are all known as ‘Sakura’.
Trees without flowers cannot be called ‘Sakura’; and the 11 species mentioned above are only called Sakura during the days when they are blossoming. The most important purpose of Sakura in ancient times was its honored function in relation to the moon calendar. Sakura in bloom means it is time for planting rice. Sakura was also a symbol of purity because its petals fell not wilted, but fresh and tender.
Propagating and growing Sakura
In the nursery of the Main Botanic Garden of the Russia Academy of Sciences (RAS), experience has been gained in propagating and growing Prunus sargentii.
In 1996, the Japanese Sakura Society presented the Main Botanic Garden with 100 two-year old sprigs of Prunus
sargentii from Hokkaido Island. Some of those plants were planted in the Japanese Garden in the Main Botanic Garden RAS and others in the nursery of the Department of Plant Propagation with the purpose of studying the propagation and cultivation of this remarkable species under Russian climatic conditions.
At the end of May, 2001, green cuttings of Prunus sargentii were treated with a stimulator of root formation (0.05% Cirkon) and planted into hotbeds for rooting. From 60 cuttings, 30 rooted; 50% is a good rate for this species.
In the middle of July, 2004, 400 green cuttings were treated with a 0.005% solution of indolebutyric acid (IBA) for 16 hours and then planted. The resulting root formation was 13%. In 2005, 270 green cuttings were taken in the middle of June and treated with 0.01% IBA for 6 hours. Good rooting was shown in 15% of the cuttings. These experiments showed that it is possible to obtain reasonable results if selection, concentration and the period of treatment of cuttings with root formation stimulators is done carefully.
Seed propagation is however a more reliable method of propagation for Sakura. Many years of observation show that although Prunus sargentii in the nursery of Main Botanic Garden blooms yearly, it blooms either sporadically or massively. In 2005, P. sargentii was exceptionally abundant in flowering and fruiting. Many fruits were set and ripened. Within the one species, P. sargentii, a diversity of color of fruits was noted: one tree produced reddish-brown fruits; the others produced fruits that were yellow and yellow-orange with red sides.
Seed were collected in two batches. The first was collected in the middle of June, 2005. The drupes were cleaned of fruit pulp and soaked in water for twenty-four hours. On the next day the seeds were planted in the beds. Many seedlings appeared in the spring of 2006, between 20-25 April. Among the 285 drupes planted, 188 sprouted: a germination rate of 66%.
The second batch of fruits was collected 10 days later (24 June 2005), cleaned and immediately planted in beds. Seedlings appeared on 4-6 May, 2006. Among 136 seeds planted, 98 sprouted. The germination rate was 72%. Prunus sargentii therefore showed a high percentage of germination when freshly collected seeds were planted without additional treatments.
During the period of vegetative growth in 2006, seedlings reached a height of 20-25 cm and a root collar thickness of 0.7 cm. Young plants demanded light and even in light shadow, grew out towards the light. Young plants passed through the winter successfully. No damaged sprouts and/or buds on living plants were noted.
In May 2007, some one-year old seedlings were planted in plastic containers for further observations of growth and development. The other seedlings remained in the beds in open ground.
The height increase of second year seedlings during one month was on average 15-25 cm. The secondary branches were formed and the main shoot was clearly defined. By the spring of 2008, the average height of plants was 75-100 cm. and some of the plants were sold because the interest and demand for this crop is very high.
It is clear that Prunus sargentii grows, flowers and fruits well at the Main Botanic Garden RAS, and that this species can be proposed for mass propagation. This species is therefore suitable for enriching the assortment of ornamental woody plants in the central part of Russia.Author’s details:
Main Botanical Gardens,
Russian Academy of Sciences,
Botanicheskaya St. 4,
Moscow 127276, Russia.