The planting Paeonia rockii method of land planted and Bonsai are essentially the same. Following are the key points:
Firstly, due to the peony root crowded, planting must be careful. If not, soil will not fill into the inside of crowded root. The empty will lead to producing mold with air contacted root. Mold gradually make root rot. And seedling sprouted, germination grows bad. At last the plant die gradually.
Secondly, both of lands planted and Bonsai do not need too much water. Particular way is following:
After seedlings are planted, we water soil pervasively. Then watering time interval should not be too short just as long as the soil keeps moist. If watered too much, soil will be airtight. Finally, with growth, leaves become yellow and seedlings go dead gradually.
Thirdly, apply fertilizer. We cannot nourish the soil too much, especially inorganic fertilizers which will hurt the root system. When the seedling leaves expand, it is best to spray fertilizer once every ten days, and the concentration should not be too high.
Fourth, trim. Pruning is one important part to seedlings. After seedlings planted, weak seedling must be pruned away. We should left 3-5 strong branches to ensure the nutrition concentrating main branches. In this way, tree peonies could grow vigorous and be floriferous.
Lastly, illumination time. Peonies like light, so seedlings cannot stock in light shortage place long-term. Only the bud fully formed before flowering, plants can be appropriately overshadow no more than 7 days in order to meet the artificial flowering period.
Technical Department of Gansu Zhongchuan Peony Nursery