A shrub or bush is a small- to medium-sized perennial woody plant. Unlike , shrubs have persistent woody stems above the ground. Shrubs can be deciduous or evergreen. They are distinguished from by their multiple Plant stem and shorter height, less than 6 m-10 m (20 ft–33 ft) tall.
Small shrubs, less than 2 m (6.6 ft) tall are sometimes termed .
Shrubs are perennial woody plants, and therefore have persistent woody Plant stem
above ground (compare with
Usually shrubs are distinguished from trees by their height and multiple stems. Some shrubs are deciduous
) and others evergreen
divided the plant world into trees, shrubs and herbs.
Some definitions state that a shrub is less than 6 m and tree is over 6 m. Others use 10 m as the cut off point.
Many species of tree may not reach this mature height because of less than ideal growing conditions, and resemble a shrub sized plant. However such species have the potential to grow taller under the ideal growing conditions for that plant.
Small, low shrubs, generally less than 2 m (6.6 ft) tall, such as lavender, Vinca and most small garden varieties of rose, are often termed .
Most definitions characterize shrubs as possessing multiple stems with no main trunk.
This is because the stems have branched below ground level. There are exceptions to this, with some shrubs having main trunks, but these tend to be very short and divide into multiple stems close to ground level. Many trees can grow in multiple stemmed forms also, such as oak
Use in parks
An area of cultivated shrubs in a park
or a garden
is known as a shrubbery
When clipped as topiary
, suitable species or varieties of shrubs develop dense foliage
and many small leafy
growing close together.
Many shrubs respond well to renewal pruning
, in which hard cutting back to a "Living stump
" results in long new Plant stem
known as "canes". Other shrubs respond better to selective pruning to reveal their structure and character.
Shrubs in common garden practice are generally considered flowering plant, though some smaller Pinophyta such as mountain pine and common juniper are also shrubby in structure. Species that grow into a shrubby habit may be either deciduous or evergreen.
, a shrub is more specifically used to describe the particular physical structural or plant life-form
of woody plants which are less than high and usually have many stems arising at or near the base. For example, a descriptive system widely adopted in Australia
is based on structural characteristics based on life-form, plus the height and amount of foliage cover of the tallest layer or dominant species
[Costermans, L. F. (1993) Native trees and shrubs of South-Eastern Australia. rev. ed. ]
For shrubs high the following structural forms are categorized:
dense foliage cover (70–100%) — closed-shrub
mid-dense foliage cover (30–70%) — open-shrub
sparse foliage cover (10–30%) — tall shrubland
very sparse foliage cover (<10%) — tall open shrubland
For shrubs less than high the following structural forms are categorized:
dense foliage cover (70–100%) — closed-heath or closed low shrubland—( North America)
mid-dense foliage cover (30–70%) — open-heath or mid-dense low shrubland—( North America)
sparse foliage cover (10–30%) — low shrubland
very sparse foliage cover (<10%) — low open shrubland
List of shrubs
Those marked with * can also develop into tree form.
Ulmus pumila celer (Turkestan elm – Wonder Hedge)
Ungnadia (Mexican Buckeye)