Pre-Planting and Planting Factors and Practices Affecting Urban Tree Growth: With a Special Focus on the Root System and Its Condition-A Review.

Trees in urban conditions struggle with many factors that reduce their growth. In many cases, newly planted trees do not survive to maturity. The trees are produced using various methods, the most popular of which are balled and burlapped (B&B) and container production. Different production methods have their cons, but in many cases, the most common problem is the root system condition-it is often poorly developed, with girdle roots, or the rootball is covered with excess soil. Deep structural roots, as this is the name of the problem related to the roots being located too deep in the soil during production or trees being placed too deep in the planting pith, have been noticed for several decades; nevertheless, they are still poorly understood. In many cases, the excess soil above the rootball is over 10 cm-such covering the rootball may lead to infection, weakening, or tree death. The problem of deep structural roots seems to be one of the most serious problems we face in the case of urban plantings. However, many other factors remain disputed-such as cutting the crowns of planted trees, removing burlap from a rootball, or planting smaller rather than larger trees. All these issues have not been resolved despite many years of study, and still require further investigation.