|This article's lead section may not adequately summarize key points of its contents. (March 2013)|
A basal shoot, root sprout, adventitious shoot, water sprout or sucker is a shoot or cane which grows from a bud at the base of a tree or shrub or from its roots. A plant that produces suckers is referred to as surculose. Root suckers may emerge some distance from the originating plant. Suckers also may arise from the stumps of trees that have been cut down.
This is a phenomenon of natural asexual spread, also known in plants as vegetative reproduction. It is a plant propagation strategy and the complex of individuals formed by a mother plant and all its clones produced form a single genetic individual, a genet. The plant suckers are clones from the mother plant. The plant will be a genome identical to that which it arose. Many species of plant reproduce through vegetative reproduction, such as the Canada thistle, cherry, Apple, Ligustrum, Hazel, and Tree of Heaven. The guava, a tropical tree, is also known to propagate through basal shoots.
The basal shoot is a variety of dispersal vector that allows the plants to reach specific habitats that are favorable for their survival. Some species send out suckers that can spread very quickly and they have the capacity of forming thick blankets of roots being able to reclaim an area that has been logged or deforested, as well as areas that have been heavily eroded and pastured. These could be considered invasive but they are used in the recovery of soils and then naturally replaced by non-pioneer species in such areas as burned lands, stabilization of land in public works and channels of rivers with large flood, hydraulic public works, reservoirs etc. They create a shaded area where new species will grow and gradually replace them in many cases.
In trees, the roots normally grow outward to about three times the branch spread. Only half of a tree's root system occurs between the trunk and the circumference of its canopy. Roots on one side of a tree normally supply the foliage on that same side of the tree. Thus when roots on one side of a tree are injured, the branches and leaves on that same side of the tree may die or wilt. For some trees however, such as the maple family, the effect of a root injury may show itself anywhere in the tree canopy.
Stolons are stems which grow at the soil surface or just below ground that form adventitious roots at the nodes, and new plants from the buds. Stolons are often called runners. Thus, not all horizontal stems are called stolons. Plants with stolons are called stoloniferous. Rhizomes, in contrast, are root-like stems that may either grow horizontally at the soil surface or in other orientations underground.
Suckers on some ornamental plants are considered undesirable by horticulturists because the plant's energy is diverted to the sucker rather than to crown growth. Suckers arising from an unwanted tree stump can be controlled with herbicides, killing the entire plant, including suckers and roots.
Suckers on a living plant cannot be removed in the same way as suckers from a stump because the application of a herbicide kills the plant. Horticulturists recommend removing suckers on trees and shrubs by tearing them away as close to the base as possible, removing soil if necessary. The buds that give rise to suckers are more completely destroyed through tearing than through cutting. In extreme cases, the root giving rise to the suckers can be separated from the tree entirely, then treated in the same way as a stump with suckers.
- Water sprouts, also called suckers