Builder, Spare That Tree!

More shade trees are probably killed each year as a result of man’s activities than are lost through disease, insects and “old age.” Projects involving street widening; laying of new sewers, gas or water mains; curbing and sidewalks; plus paving of streets, parking lots and driveways - the addition or removal of soil all exact a toll of our valuable shade trees. Death comes because valuable feeding roots are cut off or smothered. The remaining roots cannot take up the slack and the tree dies.

Many people, including some builders, do not realize that a fair-sized tree loses 20 gallons of water daily through its leaves during the growing season, or that the roots of a large elm may extend out 200 feet or more from the trunk.

Of course we expect new, widened streets, curbing and paving. Mains and sewers need to be replaced. Our homes require driveways and walks. Such progress should not be impeded, but we need to know how valuable trees can be protected and what steps to take to keep losses at a minimum.

Symptoms of root injury are generally a yellowing, wilting and drying up of the foliage followed by a die-back of various branches, or even death of the whole tree.

Some building contractors lack understanding and appreciation of trees.

Havoc can occur when a careless power shovel or bulldozer operator is let loose on a future wooded home-site without proper supervision. Damaging. often fatal, wounds to trunk. branches and roots occur frequently.

If you are contemplating building or buying a new home, better check those trees on the lot that caught your eye. What kind of trees? Are they in good condition? Find out from a neighbor if soil has been added or removed and how much. You may save yourself a lot of heartache.

When building a new home, make definite arrangements with the builder beforehand regarding what trees you want saved, how these trees are to be protected while the house is being built and details of the final grading operations.

Tree Wounds

Injuries involving the. bark and wood are primary causes of many tree troubles. Most small wounds in young, vigorously growing trees heal quickly but larger ones take much longer. Each open wound is an invitation to a trunk or root rot-producing organism (or wilt fungus), disfigurement or even death. Mechanically wounded trees, especially those which are neglected, weakened or recently transplanted arc attractive to bark beetles, borers and other damaging insects.

What can be done to protect trees from injury?

Damaged trees should be treated promptly to reduce the amount of injury which might occur. Broken branches should be cut back to the next largest branch or even the trunk. Bruised or torn bark from a bulldozer swipe should be cut back to uninjured bark.

All of the diseased or injured bark and wood, and enough of the living bark (cambium) around each wound or diseased area, should be removed to give an ellipse or oval-shaped area running lengthwise with the trunk. This will speed up healing. Paint the cut edges of the bark with orange shellac or wound dressing immediately after shaping the wound to prevent drying and injury to the living bark. Then paint the exposed wood with a permanent-type wound dressing. This may need replacing once or twice a year to protect it from wood rot fungi and other wood destroying agents.

Regardless of which wound dressing you use, the best results are secured only when the injury is checked periodically and recoated once or twice a year when the dressing cracks, peels or blisters.

Do your trees have fill soil added over the roots?

Many home builders do not realize that the addition or removal of soil from around trees may seriously damage or kill them by disturbing the delicate balance between feeding roots and the soil.

Symptoms of fill or soil removal can often be spotted by the gradual weakening of a tree together with a dying back of the twigs and then ever-enlarging branches - usually from the top down and the outside in (often most pronounced on the side where principal damage occurred.) Dwarfed yellow leaves and an abundance of sucker growth along the trunk and larger branches are other diagnostic signs. Symptoms may become visible in as short a time as a month, usually not for a year, perhaps not for several years - long after the builder (often unknown to the home buyer) has disappeared. Appearance of symptoms depends on the tree species, age and vigor of the tree and type of soil fill added, rainfall, amount of compaction or other injury, temperature, and other factors.

Naturally, the deeper the fill and the longer it is in place the more damage to the roots. A heavy clay soil, being relatively non-porous, causes the most injury especially if graded (and compacted) by a bulldozer. Gravelly fills cause the least trouble because both air and water permeate more readily to the original soil below.

What can be done to save trees from fill injury?

If a tree has been buried under a fill for a long period and the whole top is dying or dead, or sucker growth on the trunk or larger branches is the only evidence of life, nothing can be done except to cut down the tree.

Recent fills, or trees not apparently suffering seriously from older fills, can be treated. Corrective treatments should begin at once, aimed at recreating as far as possible the condidons before the fill was made.

Before exhausting time or money in attempting to correct or prevent fill injury you should carefully consider:

Is it all worth it? This will depend on the species, age, condition, expected normal life, location, and aesthetic value of the tree concerned, number of other trees on the lot, value of property and other factors. It is better to think before tackling the job rather than later.

1. If the fill is only a few inches deep (a) periodically cultivate the soil, (b) or perhaps lighten it by mixing in sand, gravel or other porous material, (c) force compressed air into the soil, and (d) fertilize the tree and water the nutrients in.

2. Where the fill is approximately one to three feet deep further work is necessary. Remove the soil directly around the trunk to the original level and construct an open-jointed dry well of bricks or stone, leaving a two foot opening around the outside of the trunk. In addition, and this is where many people fall down, dig holes down to the original soil level every few feet over the entire root area under the foliage of the tree and place four-or six-inch agricultural tile upright in them. Fertilizers are then placed in the soil as near the root zone as possible by using compressed-air drills and augers or feeding needles. The agricultural tiles should be filled with coarse gravel to prevent possible injury by stepping in them. Trees may be fed and watered in the future through these tiles. To prevent children from falling into the dry well it’s better to cover the opening with a heavy metal grating or fill the hole with a mixture of crushed rock and charcoal.

3. Where the fill is three feet or more deep, or where a very valuable tree is involved, additional work and expense are necessary:

If you are building a new home and are contemplating raising the grade around a valuable specimen tree, follow the steps outlined above. You might find it easier and cheaper in the long run to cut down the tree and transplant a young tree, of a more desirable type, in its place.

The problem of soil removal from around trees

Scraping away the topsoil from around trees usually does not damage the rootsóeven of shallow-rooted trees like elms, certain oaks, maples and sprucesónearly as much as does raising the soil grade. Most trees are not appreciably hurt when only a few inches of topsoil are removed. When too much soil is scraped away, however, many surface roots are destroyed, while others are left to sun-scald and possibly die.

Serious damage from soil removal can be prevented by:

• Neatly pruning or sawing off the exposed ends of cut or broken roots and treating these wounds with a wound dressing.
• Exposed roots should then be covered with peat moss to prevent drying.
• Build an open-jointed brick or stone wall around the trunk. This can often be planted with rock garden plants and be made a beauty spot in the yard.
• If several large roots are cut or damaged, a few of the more undesirable branches in the crown should be pruned away to maintain proper balance between roots and foliage.
• Apply fertilizer and water, especially to undisturbed areas.
• Serious injury can often be reduced by terracing a new slope around the tree instead of removing the soil away in a sloping grade. Walls should be made to prevent the terraces from eroding and exposing the roots to drying out.

Shade trees are a valuable asset to the homeowner and to the community. A home with trees (saved by joint action of builder and homeowner) providing shade and landscaping beauty is often worth several thousand dollars more than a similar house on a barren lot. It pays for you and your builder to spare that tree!

by M Shurlett

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