The words “bush” and “shrub” are often used interchangeably in casual conversation, leading to confusion about whether they represent different types of plants. In botany and horticulture, however, one term has a specific scientific definition, while the other functions as a common, generalized descriptive word. Understanding the difference requires looking at the structural characteristics and growth habit that formally classify a plant.
Defining the Shrub
A shrub is a botanical classification for a perennial woody plant that maintains persistent stems above the ground. Unlike herbaceous plants, which die back to the ground each year, shrubs possess hard, permanent, lignified stems. The defining structural characteristic is the presence of multiple stems that arise from the base of the plant or near the ground level, rather than a single, dominant trunk.
This multi-stemmed habit primarily distinguishes a shrub from a tree, which typically has a single, main trunk. Shrubs are also generally shorter than trees, with most definitions setting the maximum height between 13 and 33 feet (4 to 10 meters). Plants under 6.6 feet (2 meters) tall are sometimes categorized as subshrubs, though they share the same woody, multi-stemmed structure.
Understanding the Term Bush
The term “bush” is not a formal category used in botanical classification; instead, it is a common, vernacular noun used to describe the appearance of certain plants. In everyday language, a bush loosely refers to almost any dense, low-growing, woody plant that does not resemble a traditional tree or vine. The word often describes a growth habit that is rounded, full, and sometimes appears less maintained.
A plant referred to as a bush is characterized by thick foliage that often extends close to the ground, giving it a sprawling appearance. Terms like “rose bush” or “blueberry bush” are widely accepted in common parlance, even though these plants meet the formal definition of a shrub. This usage highlights the term’s connection to visual appearance rather than scientific structure.
The Core Distinction
The primary difference is that “shrub” is a precise, technical term in botany and horticulture, defining the plant’s woody, multi-stemmed, and perennial structure. Conversely, “bush” is a descriptive, informal term used in common language. Every plant scientifically classified as a shrub can be casually called a bush, but the reverse is not strictly true from a technical standpoint.
A shrub is a specific type of woody perennial, whereas a bush is a general descriptor for a plant with a dense, low-to-the-ground shape. The concept is similar to how all squares are rectangles, but not all rectangles are squares. All shrubs can be called bushes, but not every plant called a bush necessarily meets the strict structural criteria of a botanically defined shrub.