Recently I worked on a property that had several examples of tree planting and care that I am seeing more and more frequently – trees planted too deeply and then “volcanoed” with mulch so that they look like poles exiting lumps in the lawn. Look at old trees in the park and see that they sit on the ground with a graceful flare at the soil line. This is how all trees in the garden and the landscape should look, whether they are mulched or not. This problem is caused by planting the tree too deeply, or mounding soil on top of a root ball that was planted correctly or applying too much mulch. And this problem can, and usually does, lead to the death of the tree.
Trees may be too deep in their container or burlap ball when one buys them due to growing or harvesting issues at the nursery. They may already have girdling roots if pot-grown. It truly behooves the buyer to know as much as possible before buying trees, especially if the buyer is going to arrange for planting himself.
The same is true for shrubs and perennials. They can also arrive from the nursery root bound and then be planted too deeply. Because they are usually smaller, it is easier to see the evidence and remedy it before planting. When taking the plant from the container, if the soil is dense with roots, it should be teased away from the soil ball before planting and then put into the ground no deeper than it was in the container, or so that the place where the roots enter the soil is just at the soil line.
When trees are planted too deeply there are several problems that can and usually do occur.
Because the existing root system is planted too deep, the roots – which need water and oxygen – will begin to grow up instead of down; and worse, they will begin to grow from the bark of the portion of the trunk that is buried. These roots can become girdling roots. And because we think newly-planted trees need a lot of water, the bark below ground becomes sodden and that can cut off the system that carries food and water to the top of the tree. This is an invitation to insects and fungus.
And then there is mulch. Trees that were, in the beginning, well planted can become endangered just with the application of too much mulch. It can also smother the trunk; add too much moisture to the trunk and the cause roots to grow above the flare line, generating the problems stated above. Because tree roots need to breath, mulch should be only 1 to 2 inches deep and never against the trunk. A light mulch is best and should be used only to keep the string trimmer away from the trunk.
Plants, and especially trees, are an expensive investment. Most of us learn about them after a lot of trial and error but any research done before their purchase and planting can only be beneficial.
Jeanelle Myers is the proprietor of Jeanelle Myers Fine Gardening 631 -434 -5067.
Feel free to call for gardening discussion. [/expand]