Planting Holes

Jan 12, 2014

I am amazed how such a simple procedure can go so wrong. For avocado and citrus growers, it’s time to think about planting in the spring. And every spring and summer I get called out to diagnose trees that are failing. It often turns out that the trees have been planted too deeply. There are various ways of killing a tree, such as digging a hole too deeply and then backfilling. When the ground settles, it settles around the root collar and the tree suffocates. Or installing a dry root ball and then not irrigating soon enough. Or adding fertilizer to the planting hole which burns the roots. One of the major problems of lack education and supervision of the planting crew. Don’t assume that everyone knows how to plant a tree.

Deep planting can result in death of woody plants either because they rot in moisture saturated soils or they dry out. In either case, the symptoms are similar: wilting, sunscald or burnt leaves, lack of growth, leaf drop and eventual death of leaves, shoots and branches. Root balls planted below grade cause several problems at establishment. Since native soil surrounds the ball, there is an immediate problem with and interface between the two soil textures.   Most container media are lighter than bulk soil, which is done to make sure there is adequate drainage in the nurse. When these soil-free media are planted in soil which is of a heavier texture, the interface does not allow the water to enter the root ball.

When trees are planted too deeply, they are much more subject to fungal cankers and other pathogens that can girdle the stem, killing it and all above ground parts. Planting slightly higher than grade will prevent this. Just look for the color, textural change between the roots and stem and dig the hole no deeper than the root ball to prevent settling. Newly planted trees can’t draw water from bulk soil, not until the roots move out into the soil will they be able to absorb water. Also planting cannot be rushed, because that’s when errors in planting occur.


By Ben Faber
Author - Advisor

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