TREE CARE

By Jack O ’ Shea

With more than 20 years of experience consulting and practicing arboriculture in the Northwest and Pacific Rim , I ’ ve seen the same sad story play out again and again .

When trees in the landscape begin to decline , people hire experts like me to try to fix them . The problem ? People don ’ t notice the beautiful landscape trees were planted too deeply . Trees grow upward , and their majesty is what we notice . But to inspect , we need to look down , especially at the area of the root crown .

Hiring experts at that point may delay the inevitable . Trees and woody plants in the landscape often die due to poor cultural practices . One of the worst practices is burying the root flare of a young tree . When a tree of any age has roots that are covered too deeply with soil or mulch , contact with the soil ruins the health and integrity of the low bark .

This is because the low bark on trees is “ garden variety ” bark . Roots below ground have a different type of coverage , and are resistant to most of the rots that are present . If we wet , heat and crowd garden-variety bark , it is compromised and can be infested or infected . Fungi and insects can make a home , and , eventually , the structure of the tree can suffer as well .

Most of a landscape ’ s value can be attributed to trees . Studies have been done that determine how much a landscape costs as a measure of real estate value . It is beyond our

scope , but we as landscapers can protect these investments with a few simple observations .

Most people do not see past green leaves through to the bones of the landscape where a tree may be declining invisibly . With a little practice , you can increase your observation and detection skills to the point where you can see and solve the most common problems with root flares .

Most of what I see are roots and root flares buried under one or more inches of excess soil . The immediate area of the bark is important , and so is the root crown near the base . The flare is the actual spreading part of the root crown that buttresses the tree and holds roots in place . Pulling away soil is a boost to any tree that is suffering from too much soil .

It ’ s as simple as looking down . The root crown is defined as the area within a few inches below and above the soil line . The line at the soil level forms a “ crown ” that is important to respiration , vascular differentiation and structure . Let ’ s make sure that ’ s in the proper place .

Most trees are planted too deeply . If it looks like a telephone pole coming out of the ground , it is too deep . Research by Booth and Smiley in 2000 stated , “ 93 % of trees professionally planted are planted too deeply .” Lots of nursery-grown trees are planted too deeply in the pots . This may be a carryover from transplanting or heeling-in .

You can train your eye and hand to make sure soil is pulled back to expose the natural flare . You must look for the spreading or expanding root crown . If it isn ’ t there , gently pull away soil by hand or with any sort of digging tool — just go easy . Damage in the root crown area is magnified by the presence of soil and fungal spores that take advantage of those openings .

We can also avoid many problems that appear later if we plant in nursery plants at the correct depth . This involves measuring the planting site depth ( depth of the hole ) and making sure the roots are pointing outward .

When cutting roots , use a clean , sharp tool . I use a special pair of secateurs for underground work . Some root loss is acceptable . I have seen 50 % loss of roots improve girdled and bound tree stock . Removing that much rooting material requires staking and extra watering in most cases .

36 SportsField Management | May 2021 sportsfieldmanagementonline . com