Plums are a popular stone fruit botanically classified as trees, not bushes. They belong to the genus Prunus, which also includes other stone fruits like cherries, peaches, and apricots. These plants are woody perennials that naturally develop a single, defined trunk and a branching canopy. This structure confirms that plums grow on trees, unlike the multi-stemmed, low-growing structures characteristic of bushes.
Plum Trees: The Definitive Answer
Plum trees, specifically European plum (Prunus domestica) and Japanese plum (Prunus salicina), are deciduous trees with a distinct growth habit. Standard European varieties can reach mature heights between 15 and 25 feet. Japanese plums can grow to a similar height, sometimes up to 33 feet, often displaying a more upright growth pattern.
The fundamental structure of a plum tree involves a central leader or trunk that supports a canopy of woody branches. This single-stemmed, perennial growth is designed to support the weight of a mature fruit crop and reach for sunlight. The flowers appear in early spring, often before the leaves, providing a distinct ornamental feature before the fruit develops.
Why Plum Trees Are Sometimes Mistaken for Bushes
The confusion regarding whether a plum is a tree or a bush arises primarily from modern cultivation practices. Growers often use heavy pruning and training techniques to keep trees shorter and wider, giving them a dense, bush-like appearance. Techniques like open-center pruning intentionally remove the central leader to create a goblet shape. This improves light penetration and air circulation, making the tree look more like a large shrub.
Many plum trees are grafted onto dwarfing or semi-dwarfing rootstocks, which significantly restrict the plant’s ultimate size. For example, trees on a Pixy rootstock may only reach about 10 feet tall, a size easily manageable in a small garden. These smaller trees still retain the woody perennial structure of a tree. They are often described as “bush trees” in horticultural terms to indicate their small, manageable size.
Essential Needs for Growing Plum Trees
Successful plum cultivation requires careful attention to a few environmental factors to ensure strong growth and fruit production. Plum trees require full sun exposure, needing at least six hours of direct sunlight daily to properly develop fruit and maintain health. Insufficient light can lead to poor fruit set and reduced vigor.
The trees also need well-draining soil, as they are susceptible to root rot in waterlogged conditions. Loamy soil that retains moisture without becoming saturated is ideal, often with a slightly acidic to neutral pH between 6.0 and 7.0. Proper soil drainage is necessary for establishing a deep, healthy root system.
A third requirement is the accumulation of chill hours during the winter dormancy period. Chill hours refer to the total time the tree spends in temperatures between 32°F and 45°F. This chilling is necessary to break dormancy and enable uniform flowering in the spring. Depending on the variety, plum trees may need between 275 and 1,200 chill hours to ensure consistent fruit production.