How to Grow Chinese Sweet Plum (Sageretia thea)? A Full Breakdown of the Latest Planting Techniques

Sageretia thea is certainly no stranger to bonsai enthusiasts. As one of the Seven Sages of bonsai, Zhang Yongfa praised it in his poem: “red buds covering the tree in spring, green shade like a canopy in summer, tiny flowers with a faint fragrance in autumn, and iron-hard gnarled branches in winter”. The roots and trunk of Sageretia thea are peculiar, and as a whole it appears vigorous and powerful, classical and elegant, truly a top-grade bonsai.

But Sageretia thea also has a characteristic that gives people headaches, namely branch loss in Sageretia thea: in a finished work, a certain branch may suddenly die, commonly known as retiring after success. A perfectly good potted work, condensing years of the maker's hard work, is nearly ruined because of partial branch loss, which is truly distressing. The reason is that the branch and trunk cortex of Sageretia thea is relatively thin, and its nutrient transport is longitudinal, so daily care and management of Sageretia thea place very high demands.

1. Keep potted Sageretia thea growing vigorously.

The prerequisite for vigorous growth is branches emerging on all four sides of the trunk. When selecting and retaining structural branches on a sprouted stump, this point should be fully noted. Even useless branches at the top of the trunk outside the intended shape should not all be cut off at once; wait until the tree's vigor recovers, then gradually remove them according to shaping needs. If cut off all at once, partial dieback may occur, seriously affecting the growth and appearance of the stump.?

As everyone knows, balancing tree vigor is extremely important for the growth of a stump. Only by enabling the roots, trunk, branches and leaves of the stump to grow vigorously in all directions can a stump that suffered severe damage when the material was reworked recover its body, thereby accumulating sufficient nutrients and preparing for future branch training and shaping.

Branch training and shaping of Sageretia thea: use pruning as much as possible, and use wire wrapping as little as possible or not at all. Because the cortex of Sageretia thea is very thin, wire wrapped around branches will seriously affect the branches' nutrient transport, and over time will cause the branches' growth to weaken; as this progresses, branch loss is unavoidable. After Sageretia thea has taken shape, it also must not be pruned excessively, at most twice a year: once during the plum rain season, and once before budding is best. After Sageretia thea drops its leaves, if thorough pruning is done to improve viewing, it should be brought indoors in time before winter freezing, because exposed pruning cuts will freeze in severe cold weather, damaging the buds near the cuts, or even freezing small branches to death, affecting normal budding of branches the following year.

2. Potted Sageretia thea should avoid severe dehydration.

Severe dehydration is one of the main causes of branch loss in potted Sageretia thea, so keeping the potting soil moist is extremely important for potted Sageretia thea. We all know that when a plant suffers severe water deficit, its cells lose turgor pressure, which is caused by transpiration water loss temporarily exceeding root water uptake. In other words, the water content in the potting soil equals or is lower than the amount of water needed for transpiration, especially during the high-temperature summer season. Although potted Sageretia thea that has suffered severe dehydration can recover normal leaf growth after rewatering, it will inevitably cause some plant cells to die, resulting in growth pause. Many bonsai friends must have had this experience: after rescue watering, potted Sageretia thea that suffered dehydration does not dry up and die, but for a long period afterward, the wet-dry cycle of the potting soil becomes noticeably longer and the number of waterings noticeably decreases. The reason is that after severe dehydration, some cells in the roots, trunk and branches die, and transpiration and transport capacity decline. Due to the unique physiological characteristics of Sageretia thea, the growth pause caused by the death of some root, trunk and branch cells will inevitably hinder the growth of the corresponding branches, and over time branch loss is unavoidable. In fact, this is also a self-regulating function of plants: because the growth balance of the whole plant is disrupted, it will abandon some branches to maintain the balance of the whole plant's growth, and such situations are also common in plant growth in nature.

3. Potted Sageretia thea must be repotted and have its soil changed frequently.

Sageretia thea is deeply loved by bonsai enthusiasts because it has extremely strong sprouting ability, making the selection of branch points very convenient. We know that tree species with strong sprouting ability also have extremely developed root systems. For Sageretia thea under potted conditions, because its root growth space is limited, if it is not repotted for a long time, its roots will grow circling along the pot wall, forming a “root nest”, seriously affecting the roots' absorption of water and nutrients, and further affecting the normal growth of the whole plant. Therefore, potted Sageretia thea must be repotted and have its soil changed frequently. Small and medium-sized potted Sageretia thea must be repotted once a year; large ones can be repotted somewhat later, but preferably once every other year. When repotting, appropriate pruning of the roots can be combined with the cultivation of multi-level roots. Sageretia thea is not very strict about soil requirements; it can grow normally within a pH range of 5.5——, but the soil must be loose and permeable.

The above are the techniques that need to be grasped with priority when growing Sageretia thea. Growing Sageretia thea requires years of effort, and if a potted Sageretia thea work is scrapped because of branch loss in Sageretia thea, it is truly a pity. Therefore, in daily care, one should observe and summarize diligently to avoid the occurrence of branch loss in Sageretia thea.