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. Many botanical groups have species that are shrubs, and others that are trees and herbaceous plants instead.
Fruit trees are grown in a variety of shapes, sometimes to please the eye but mainly to encourage fruit production. The form or shape of fruit trees can be manipulated by pruning and training. Shaping and promoting a particular tree form is done to establish the plant in a particular situation under certain environmental conditions, to increase fruit yield, and to enhance fruit quality. For example, pruning a tree to a pyramid shape enables trees to be planted closer together. An open bowl or cup form helps sunlight penetrate the canopy, thus encouraging a high fruit yield whilst keeping the tree short and accessible for harvesting. Other shapes such as cordons, espaliers and fans offer opportunities for growing trees two dimensionally against walls or fences, or they can be trained to function as barriers.
Fruit tree pruning is the cutting and removing of selected parts of a fruit tree. It spans a number of horticultural techniques. Pruning often means cutting branches back, sometimes removing smaller limbs entirely. It may also mean removal of young shoots, buds, and leaves.
Pollarding is a pruning system involving the removal of the upper branches of a tree, which promotes the growth of a dense head of foliage and branches. In ancient Rome, Propertius mentioned pollarding during the 1st century BCE. The practice has occurred commonly in Europe since medieval times, and takes place today in urban areas worldwide, primarily to maintain trees at a determined height or to place new shoots out of the reach of grazing animals.
In botany, apical dominance is the phenomenon whereby the main, central stem of the plant is dominant over other side stems; on a branch the main stem of the branch is further dominant over its own side twigs.
Arboriculture is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants. The science of arboriculture studies how these plants grow and respond to cultural practices and to their environment. The practice of arboriculture includes cultural techniques such as selection, planting, training, fertilization, pest and pathogen control, pruning, shaping, and removal.
An arborist, tree surgeon, or arboriculturist, is a professional in the practice of arboriculture, which is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants in dendrology and horticulture.
Espalier is the horticultural and ancient agricultural practice of controlling woody plant growth for the production of fruit, by pruning and tying branches to a frame. Plants are frequently shaped in formal patterns, flat against a structure such as a wall, fence, or trellis, and also plants which have been shaped in this way.
Thinning is a term used in agricultural sciences to mean the removal of some plants, or parts of plants, to make room for the growth of others. Selective removal of parts of a plant such as branches, buds, or roots is typically known as pruning.
Girdling, also called ring-barking, is the circumferential removal or injury of the bark of a branch or trunk of a woody plant. Girdling prevents the tree from sending nutrients from its foliage to its roots, resulting in the death of the tree over time, and can also prevent flow of nutrients in the other direction depending on how much of the xylem is removed. A branch completely girdled will fail and when the main trunk of a tree is girdled, the entire tree will die, if it cannot regrow from above to bridge the wound. Human practices of girdling include forestry, horticulture, and vandalism. Foresters use the practice of girdling to thin forests. Extensive cankers caused by certain fungi, bacteria or viruses can girdle a trunk or limb. Animals such as rodents will girdle trees by feeding on outer bark, often during winter under snow. Girdling can also be caused by herbivorous mammals feeding on plant bark and by birds and insects, both of which can effectively girdle a tree by boring rows of adjacent holes.
A branch collar is the "shoulder" between the branch and trunk of woody plants; the inflammation formed at the base of the branch is caused by annually overlapping trunk tissue. The shape of the branch collar is due to two separate growth patterns, initially the branch grows basipetally, followed by seasonal trunk growth which envelops the branch.
The crown of a plant is the total of an individual plant's aboveground parts, including stems, leaves, and reproductive structures. A plant community canopy consists of one or more plant crowns growing in a given area.
A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposed to herbaceous plants that die back to the ground until spring.
In viticulture, the canopy of a grapevine includes the parts of the vine visible aboveground - the trunk, cordon, stems, leaves, flowers, and fruit. The canopy plays a key role in light energy capture via photosynthesis, water use as regulated by transpiration, and microclimate of ripening grapes. Canopy management is an important aspect of viticulture due to its effect on grape yields, quality, vigor, and the prevention of grape diseases. Various viticulture problems, such as uneven grape ripening, sunburn, and frost damage, can be addressed by skillful canopy management. In addition to pruning and leaf trim, the canopy is often trained on trellis systems to guide its growth and assist in access for ongoing management and harvest.
A defensible space, in the context of fire control, is a natural and/or landscaped area around a structure that has been maintained and designed to reduce fire danger. The practice is sometimes called firescaping. "Defensible space" is also used in the context of wildfires, especially in the wildland-urban interface (WUI). This defensible space reduces the risk that fire will spread from one area to another, or to a structure, and provides firefighters access and a safer area from which to defend a threatened area. Firefighters sometimes do not attempt to protect structures without adequate defensible space, as it is less safe and less likely to succeed.
The use of vine training systems in viticulture is aimed primarily to assist in canopy management with finding the balance in enough foliage to facilitate photosynthesis without excessive shading that could impede grape ripening or promote grape diseases. Additional benefits of utilizing particular training systems could be to control potential yields and to facilitate mechanization of certain vineyard tasks such as pruning, irrigation, applying pesticide or fertilizing sprays as well as harvesting the grapes.
Bonsai cultivation and care involves the long-term cultivation of small trees in containers, called bonsai in the Japanese tradition of this art form. Similar practices exist in other Japanese art forms and in other cultures, including saikei (Japanese), penjing (Chinese), and hòn non bộ (Vietnamese). Trees are difficult to cultivate in containers, which restrict root growth, nutrition uptake, and resources for transpiration. In addition to the root constraints of containers, bonsai trunks, branches, and foliage are extensively shaped and manipulated to meet aesthetic goals. Specialized tools and techniques are used to protect the health and vigor of the subject tree. Over time, the artistic manipulation of small trees in containers has led to a number of cultivation and care approaches that successfully meet the practical and the artistic requirements of bonsai and similar traditions.
Leucostoma canker is a fungal disease that can kill stone fruit. The disease is caused by the plant pathogens Leucostoma persoonii and Leucostoma cinctum (teleomorph) and Cytospora leucostoma and Cytospora cincta (anamorphs). The disease can have a variety of signs and symptoms depending on the part of the tree infected. One of the most lethal symptoms of the disease are the Leucostoma cankers. The severity of the Leucostoma cankers is dependent on the part of the plant infected. The fungus infects through injured, dying or dead tissues of the trees. Disease management can consist of cultural management practices such as pruning, late season fertilizers or chemical management through measures such as insect control. Leucostoma canker of stone fruit can cause significant economic losses due to reduced fruit production or disease management practices. It is one of the most important diseases of stone fruit tree all over the world.
A branch attachment is where a branch is attached to the trunk of a tree. Three types of branch attachment are recognized due to differences in the anatomical position of buds that form them. Two key components contribute to the mechanical strength and toughness of the attachment: interlocking wood grain at the top of the attachment and an embedded knot that often lies within the attachment. A common malformation of a branch attachment is the inclusion of bark within the join, which can weaken the attachment.
