Most site problems are due to lack of oxygen for tree roots. When planting a tree, choose one that is naturally adapted to your site conditions.
|shallow soils||compacted clay soils,
|confined rooting areas|
|For compacted, wet soils use small trees that are native to wet sites, like Sweetbay magnolia or serviceberry.||Plant trees that mature to less than 40 ft high if a confined area is less than 10 ft wide.|
Changes in soil grade also are frequent causes of tree failure. Even a few inches of fill or soil removal can cause extensive root damage. If possible, never remove or add large amounts of soil within the drip line of a tree. The table below lists species with known sensitivity/resistance to changes in soil grade:
|most oaks||Pin oak|
When soil air is decreased by filling, certain gases and chemicals increase and become toxic to roots. Symptoms may appear within months or years after filling has occurred.
- The extent of injury from filling varies with the species, age, and condition of the tree; the depth and type of fill; and drainage.
- Clay soils cause the most damage because the fineness of the soil shuts out air and water more than a gravelly or coarse soil.
- Three to four inches of soil can be added to small areas under the tree provided the soil texture is coarser than the native soil. Finer textured soils should not be used for filling.