Maintaing New Trees


Trees need maintenance throughout their lives, but it is particularly important during the period of establishment after transplanting. Extra care must be given until new roots are regenerated.

 

Watering

Proper watering is the single most important aspect of maintenance of transplanted trees. The reduced root system of the newly transplanted tree is concentrated in a small soil volume with very little water available to it. Regular watering will be necessary.

It is also easy to overwater, especially if the planting site is poorly drained. In the first few months after a tree is planted, a tree draws most of its moisture from roots within the root ball. The root ball can dry out in a few days, though surrounding soils remain moist. The only way to know is to probe the soil in the root ball frequently to check its moisture. The soil one to two inches under the surface should form a ball when squeezed. If it crumbles, it is too dry. The soil probe is ideal for this. Dryness can be accurately estimated with some practice by inserting a metal rod into the soil. The drier the soil, the more resistance to penetration. Digging with a small shovel also works, but can result in considerable root damage if done too often. Even after trees are well established, they should be watered generously during periods of drought.

 

Fertilization

It is unlikely that any nutrient is limiting the growth of the tree immediately after transplanting. Drought stress is probably the most limiting factor at that time. Fertilization should be delayed for a season or two after the tree is planted (longer for larger trees). Once vigor is regained, fertilize trees with a nitrogen fertilizer at a rate of up to six pounds of actual nitrogen per 1,000 square feet per year (approximately a 2-pound coffee can of ammonium sulfate spread over a 10-foot diameter circle). This is a large amount of fertilizer and will have to be either watered in well or split into more than one application. The amounts of potassium, phosphorous, and other nutrients in soils vary and these nutrients may not need to be added. Proper soil testing will determine what other elements are required. Always apply fertilizers evenly over the entire root zone, and remember that the roots can grow well beyond the side branches in only a few years.

 

Pruning

Proper tree selection will eliminate the need for major pruning to control size in the future. Planting in the proper location will minimize the need for pruning to clear buildings and walkways as the tree grows. Once a good branch structure has been achieved, periodic removal of deadwood will be the only pruning requirement if a tree is well matched to its site.

 

*Information on Planting Trees excerpted from Selecting & Planting Trees The Morton Arboretum, Lisle, Illinois