Answer: Most fruit trees are grafted in the nursery about 2-4 inches above the soil line. Bareroot grafted trees that you purchase from the nursery should have a visible “soil line” – that line on the trunk where the soil came up to at the time the tree was dug prior to shipping. Ideally, when this bareroot tree is planted in your orchard, you should ensure that the same soil line on the bark is at the actual level of the settled soil after planting. A good, rule-of-thumb, therefore, is to ensure that the graft union is 2-4 inches above the soil once planted. Because of the convenience of using tractor-mounted tree planters to plant thousands of trees per day, if the resulting furrow is too deep, many trees can be planted incorrectly in a short period of time. In some cases in commercial orchards, I have observed trees planted 8 or more inches too deep. This is particularly a problem on heavier soils. Planting too deep can stunt tree growth, lead to soil compaction and a lack of oxygen for feeder roots, and even adversely impact tree stability. Under conditions such as these, if soils become saturated because of excess rain, trees may die from waterlogging or may be predisposed to infection by phytophthora root rot.
|This young tree was planted too deep. One scaffold is completely dead. Some other branches are dead or dying.
||Soil was removed from the base of this tree to expose the graft union. At least 8 inches of soil needed to be removed before the first roots could be found.
|Tree immediately after extraction from the soil. Note three areas on trunk where a small amount of bark was removed.
||Close up of trunk for tree removed from the ground. Tape measure notes three spots where bark was partially removed (nicked with knife). Bottom nick (0 inch on tape measure) corresponds to the soil line where the tree was planted in the nursery. The tree should have been planted at this depth. Middle nick (4 inch on tape measure) is where the graft union occurred. Top nick (8-9 inches on tape measure) corresponds to the location where the soil was at planting (i.e., 8-9 inches too deep).
|Bark on side of the tree with the dead scaffold was removed from the trunk beginning at soil line originally planted in nursery (0 inch on tape measure) up to depth planted in the field (9 inches on tape measure). Underlying tissue is dead indicating symptoms of Phytophthora crown rot.