Sheringham Park in the context of "Shrubberies"

A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple stems and shorter height, less than 6–10 m (20–33 ft) tall. Small shrubs, less than 2 m (6.6 ft) tall are sometimes termed as subshrubs.

Some define a shrub as less than 6 m (20 ft) and a tree as over 6 m tall. Others use 10 m (33 ft) as the cutoff point for classification. Many trees do not reach this mature height because of hostile, less than ideal growing conditions, and resemble shrub-sized plants. Others in such species have the potential to grow taller in ideal conditions. Some only last about five years in good conditions. Others, usually larger and more woody, live beyond 70 years. On average, they die after eight years.

A shrubbery, shrub border or shrub garden is a part of a garden where shrubs, mostly flowering species, are thickly planted. The original shrubberies were mostly sections of large gardens, with one or more paths winding through it, a less-remembered aspect of the English landscape garden with very few original 18th-century examples surviving. As the fashion spread to smaller gardens, linear shrub borders covered up walls and fences, and were typically underplanted with smaller herbaceous flowering plants. By the late 20th century, shrubs, trees and smaller plants tend to be mixed together in the most visible parts of the garden, hopefully blending successfully. At the same time, shrubs, especially very large ones, have become part of the woodland garden, mixed in with trees, both native species and imported ornamental varieties.

The word is first recorded by the OED in a letter of 1748 by Henrietta Knight, Lady Luxborough to the fanatical gardener William Shenstone: "Nature has been so remarkably kind this last Autumn to adorn my Shrubbery with the flowers that usually blow at Whitsuntide". The shrubbery developed to display exciting new imported flowering species, initially mostly from the East Coast of British America, and quickly replaced the older formal "wilderness", with compartments of smaller trees surrounded by hedges, and little colour. It was a further part of the garden, beyond the terrace and flower garden that the house usually opened onto, and when mature provided shade on hot days, some shelter from a wind, and some privacy.

A woodland garden is a garden or section of a garden that includes large trees and is laid out so as to appear as more or less natural woodland, though it is often actually an artificial creation. Typically it includes plantings of flowering shrubs and other garden plants, especially near the paths through it.

The woodland garden style is essentially a late 18th- and 19th-century creation, though drawing on earlier trends in gardening history. Woodland gardens are now found in most parts of the world, but vary considerably depending on the area and local conditions. The original English formula usually features tree species that are mostly local natives, with some trees and most of the shrubs and flowers from non-native species. Visitable woodlands with only native species tend to be presented as nature reserves. But for example in the United States, many woodland gardens make a point of including only native or regional species, and often present themselves as botanical gardens.