A. Trimming: Refer to the current edition or revision of "Pruning Standards For Shade Trees", "Natural Target Pruning", or the "American Association Of Nurseryman Standards". These publications are available at the public ways and parks office building, 1875 Monroe Boulevard.
B. Spraying: See publications referenced above.
C. Removal: Trees will be removed in accordance with accepted industry standards and procedures and by following three (3) minimum requirements: 1) limbs and branches larger than four inches (4") in diameter shall be lowered to the ground through the use of ropes or other mechanical devices if the fall cannot be controlled; 2) extreme care shall be taken so as to prevent any and all damage to turf, hard surfaces and structures; and 3) stumps shall not be left higher than six inches (6") above ground level.
1. Removal Criteria For Trees On City Property: Street trees and park trees shall be removed only when authorized by the urban forester and a removal permit has been issued. Authorization may be for any of the following reasons:
a. The tree is infected with a pathogen, insect, or disease.
b. Public work requirements dictate work be done around the tree will kill or render it a hazard.
c. It poses a severe hazard that is beyond the point of correction.
d. It severely interferes with the growth and development of a more desirable public tree.
e. The aesthetic values are so poor that the site is visually enhanced by the tree's removal.
f. It is dead, dying, and/or deteriorating and is a hazard to property and/or people.
g. It is no longer economically feasible to maintain, e.g., maintenance costs exceed environmental benefits derived from declining health conditions.
h. It is causing damage to infrastructure, e.g., sewer line, water, etc., which is not correctable using other tree maintenance methods.
2. Removal Criteria For Stumps On City Property: Stumps shall be removed to a depth of no less than twelve inches (12") below the finished grade. Portions of the stump or surface roots that cannot be removed with the use of a stump grinder shall be treated immediately upon completion of grinding with a stump killing compound. Application of such treatments will be in full compliance with the chemical label and Utah state chemical application laws.
D. Planting: See subsections 1900-6A through E of this policy.
E. Pruning Specifications:
1. Pruning As Maintenance Practice: Pruning is a horticultural practice based on science and aesthetics and is a preventive and corrective maintenance practice. All pruning of street trees, park trees, or public trees shall be done in accordance with the current editions of the National Arborist Association's "Pruning Standards For Shade Trees", and the "Natural Target Pruning", the National Tree Care Industry Association Standards and the American national standards for pruning, ANSI A300, unless otherwise specified. All pruning performed by individuals including Ogden City forestry personnel will be in accordance with the Ogden City urban forestry ordinance and these regulations. Copies of these specifications shall be available through the urban forester for public distribution. Additional copies are available at the Ogden public ways and parks office located at 1875 Monroe Boulevard and the Ogden City recorder's office located at 2484 Washington Boulevard, third floor, upon request.
2. Final Cuts: All final pruning cuts shall be made sufficiently close to the trunks or parent limb, without cutting into the "branch collar" or leaving a protruding stub, so as to favor the earliest possible covering of the wound by natural wound wood growth. Excessively deep flesh cuts that produce large wounds or weaken the tree at the cut shall not be made.
3. Pruning Of Large Limbs: Whenever pruning cuts are to be made while removing limbs too large to hold securely in one hand during the cutting operation, the limbs shall be cut off first one to two feet (2') beyond the intended final cut. Then the final cut shall be made in a manner to prevent unnecessary tearing back of the bark and/or wood.
4. Large Branches To Be Secured: Whenever necessary, to prevent tree or property damage, large branches shall be secured by ropes or other equipment and lowered safely to the ground in a controlled manner.
5. Living Branches: The best time to prune living branches is in the dormant growth period of a tree or very early in the spring before leaves form. Some tree species have a free flow sap and will "bleed" if pruned in late winter or early spring. Maples, birch, honeylocust, elms and walnut trees should be pruned when they are actively growing to prevent "bleeding". Late summer or early fall is ideal. Dead and dying branches can and should be pruned and removed at any time.
6. Treatment Of Pruning Cuts: Treatment of pruning cuts with a sealer is not recommended. Wound dressings do not stop decay or inhibit rot and they can be detrimental to the natural healing of pruning cuts. If a pruning sealer is used, materials nontoxic to the wood must be used, and care taken to treat only the exposed wood with a thin coat of aerosol spray.
7. Maintenance Of Tools And Saws: All cutting tools and saws used in making tree pruning cuts shall be kept sharpened to result in final cuts with smooth, clean wood surfaces and secure, healthy bark remaining adjacent thereto.
8. Diseased Trees: On trees known to be diseased, pruning tools are to be disinfected after each cut and between trees. Sterilize pruning tools with methyl alcohol at two (2) cups of alcohol per gallon of water or bleach at one cup of bleach per gallon of water.
9. Sidewalk And Street Clearance: In removing the lower bottom branches of trees for sidewalk clearance, care should be given to an aesthetic appearance. Over the street clearance shall be kept to a minimum of twelve feet (12') above the paved surface of the street and seven feet (7') above the surface of the public sidewalk or pedestrianway.
10. Topping: Topping, which is removal of all branches in the upper portion of the tree's crown for the purpose of reducing the tree's overall height, is not an acceptable pruning practice and will not be allowed on street trees, park trees and/or public trees, unless authorized by the urban forester. These methods of pruning will be used only as a last resort if no other acceptable tree pruning methods can be used and only in a manner specified by the urban forester.
11. Prohibited Equipment: No person shall be allowed to use prohibited equipment to include shoes with spikes, spurs, climbing irons, or any other footwear that may cause injury to the trees being trimmed under the terms of these regulations. Climbing gear of this nature can only be used during tree removal operations.
12. Tree Workers: At least one responsible tree worker will serve to coordinate safe operating ground conditions. All work shall be done in accordance to and in conjunction with the Ogden City police department and the "Manual On Uniform Traffic Control Devices". The tree workers will install proper barricades, signs and warning devices, as necessary for sidewalk and traffic closure and control, during any and all street tree pruning work.
13. Health And Appearance Of Trees: The authority to prune street trees, park trees and/or public trees does not authorize tree workers to cut back sound, healthy tree limbs in such a manner that the health and/or appearance of the tree(s) is impaired. When pruning trees, one should have in mind to make them shapely, symmetrical and typical of their species. It is recommended that public trees be pruned either by the city forestry personnel or by an ISA certified arborist.
14. Pruning Classes And Standards For Shade Trees:
a. Pruning will be done according to the latest revision of standards of the National Arborist Association for shade tree class I, II, III, or IV pruning as described herein. The urban forester will decide pruning class requirements and will indicate them in the pruning permit obtained prior to conducting the work. In addition, pruning will follow Utah shade tree pruning standards as well as the American national standards for tree care operations.
b. Generally, pruning shall consist of conforming to class II, medium pruning, and lifting the lower bottom branches of trees for under clearance as directed by the urban forester. The urban forester will require additional pruning for street intersection and house clearing.
c. The urban forester will direct under clearance pruning to provide for pedestrian and vehicular clearance. Clearance heights shall be determined at a point over the sidewalk and at the lowest point of branch overhang over the street. Clearance heights shall be maintained at a minimum of seven feet (7') over sidewalks and twelve feet (12') over the street surface on less traveled residential streets. Clearance heights on higher traffic collector and arterial streets shall be maintained at a minimum of seven feet (7') over sidewalks and sixteen feet (16') over the street surface.
15. Classifications Of Pruning:
a. Class I fine pruning shall consist of the removal of dead, dying, diseased, interfering, objectionable, obstructing, and weak branches, as well as selective thinning to lessen wind resistance. The removal of such described branches is to include those on the main trunks, as well as those inside the leaf area. An occasional branch, up to one-half inch (1/2") diameter, as described above, may remain within the main leaf area to its full length when it is not practical to remove it. The following specifications shall apply:
(1) All cuts shall be made sufficiently close to the trunk or parent limb, without cutting into the branch collar or leaving a protruding stub, so that closure can readily start under normal conditions. Clean cuts shall be made at all times.
(2) It is necessary to precut branches too heavy to handle to prevent splitting or peeling the bark. Where necessary to prevent tree or property damage, branches shall be lowered to the ground by proper ropes or equipment.
(3) Remove the weaker or least desirable of crossed or rubbing branches. Such removal should not leave large holes in the general outline of the tree.
(4) Treatment of cuts and wounds, with tree wound dressing, is not recommended but is optional except where open wounds in certain trees may attract insects that carry disease or allow fungal invasion. If such treatment is made, materials nontoxic to the cambium layer must be used, and care taken to treat only the exposed wood with a thin coat of dressing.
(5) On trees known to be diseased, tools are to be disinfected with methyl alcohol at two (2) cups per gallon of water or bleach at one cup of bleach per gallon of water after each cut and between trees where there is known to be a danger of transmitting the disease on tools.
(6) Old injuries are to be inspected. Those not closing properly, and where the callus growth is not already completely established, should be reported to the urban forester for the purpose of inspection. Once inspected, the urban forester will decide the best method or practice available to remedy the situation.
(7) Where practical, all visible girdling roots shall be treated as follows: a) cut root at either end, b) notch root in center with chisel, and c) remove entire root without injuring the back or parent stem.
(8) The presence of any structural weakness, disease conditions, decayed trunk/branches, split crotches/branches, should be reported to the city for recommended corrective measures.
b. Class II medium pruning shall consist of the removal of dead, dying, diseased, interfering, objectionable and weak branches on the main trunks as well as those within the leaf area. An occasional branch up to one inch (1") in diameter may remain within the main leaf area where it is not practical to remove it. The following specifications shall apply:
(1) All cuts shall be made sufficiently close to the trunk or parent limb, without cutting into the branch collar or leaving a protruding stub, so that closure can readily start under normal conditions. Clean cuts shall be made at all times.
(2) It is necessary to precut branches too heavy to handle to prevent splitting or peeling the bark. Where necessary, to prevent tree or property damage, branches shall be lowered to the ground by proper ropes or equipment.
(3) Treatment of cuts and wounds, with tree wound dressing, is optional except where open wounds in certain trees may attract insects that carry disease or allow fungal invasion. If such treatment is made, materials nontoxic to the cambium layer must be used, and care taken to treat only the exposed wood with a thin coat of dressing.
(4) On trees known to be diseased, tools are to be disinfected with methyl alcohol at two (2) cups per gallon of water or bleach at one cup of bleach per gallon of water after each cut and between trees where there is known to be a danger of transmitting the disease on tools.
(5) Old injuries are to be inspected. Those not closing properly and where the callus growth is not already completely established should be reported to the urban forester for the purpose of inspection. Once inspected, the urban forester will decide the best method or practice available to remedy the situation.
(6) All girdling roots visible to the eye are to be reported to the urban forester or are to be severed as described in class I fine pruning.
(7) The presence of any structural weakness, disease conditions, decayed trunk or branches, split crotches or branches should be reported to the urban forester for the purpose of inspection. Once inspected the urban forester will decide the best time and the best solution to alleviate hazardous situations.
c. Class III coarse pruning shall consist of the removal of dead, diseased or obviously weak branches, two inches (2") in diameter or greater. The following specifications shall apply:
(1) All cuts shall be made sufficiently close to the trunk or parent limb, without cutting into the branch collar or leaving a protruding stub, so that closure can readily start under normal conditions. Clean cuts shall be made at all times.
(2) It is necessary to precut branches too heavy to handle to prevent splitting or peeling the bark. Where necessary, to prevent tree or property damage, branches shall be lowered to the ground by proper ropes or equipment.
(3) Treatment of cuts and wounds with tree wound dressing is optional except where open wounds in certain trees may attract insects that carry disease or allow fungal invasion. If such treatment is made, materials nontoxic to the cambium layer must be used, and care taken to treat only the exposed wood with a thin coat of dressing.
(4) On trees known to be diseased, tools are to be disinfected with methyl alcohol at two (2) cups per gallon of water or bleach at one cup of bleach per gallon of water after each cut and between trees where there is known to be a danger of transmitting the disease on tools.
(5) The presence of any structural weakness, disease conditions, decayed trunk or branches, split crotches or branches, should be reported to the urban forester for the purpose of inspection. Once inspected the urban forester will decide the best time and the best solution to alleviate hazardous situation.
d. Class IV cutting back or drop crotch pruning shall consist of the reduction of tops, sides, under branches or individual limbs. This practice is to be undertaken only in cases of utility line interference, where certain portions of the roots or root systems have been severed or severely damaged, when there is unusual and rapid tree growth, where it is necessary to reduce the topsides or under branches, or for specific topiary training or dwarfing. The following specifications shall apply:
(1) All cuts shall be made sufficiently close to the trunk or parent limb, without cutting into the branch collar or leaving a protruding stub, so that closure can readily start under normal conditions. Clean cuts shall be made at all times.
(2) It is necessary to precut branches too heavy to handle to prevent splitting or peeling the bark. Where necessary, to prevent tree or property damage, branches shall be lowered to the ground by proper ropes or equipment.
(3) Remove crossed or rubbing branches and branches that exhibit weak unions or are less desirable due to their location within the crown. Such removal should not leave large holes in the general outline of the tree.
(4) Treatment of cuts and wounds with tree wound dressing is optional except where open wounds in certain trees may attract insects that carry disease or allow fungal invasion. If such treatment is made, materials nontoxic to the cambium layer must be used, and care taken to treat only the exposed wood with a thin coat of dressing.
(5) Old injuries are to be inspected. Those not closing properly and where the callus growth is not already completely established should be reported to the urban forester for the purpose of inspection. Once inspected, the urban forester will decide the best method or practice available to remedy the situation.
(6) Generally, in reducing size (cutting back), not more than one-third (1/3) of the total area should be reduced at a single operation. When cutting back trees, only drop crotch as much as necessary. Where practical, natural trimming shall be accomplished without cutting back to small suckers. The smaller limbs and twigs are to be removed in such a manner as to leave the foliage pattern evenly distributed. When making a drop crotch cut, all effort should be made to cut back to a lateral that is at least one-third (1/3) of the diameter of the cut being made on the main branch.
(7) In reducing overall size, attention is to be given to the symmetrical appearance of the crown. Trees should be shaped to remain in an appearance, which is true to crown characteristics and typical of their species. Sides shall be reduced in order to maintain a tree like form.
(8) When cutting back trees, one should have in mind to make them true to crown characteristics and typical of their species.
(9) On thin barked trees, just enough limbs shall be removed to get the effect wanted without admitting too much sunlight to the trunk of the tree or the top of large branches. Care should be taken with the following species: lindens, maples, beeches, apples, oaks, and other trees susceptible to sun scald growing in different geographical areas. Doing work on susceptible species during late winter or early spring may minimize the above damage.
(10) In lifting the lower bottom branches of trees for under clearance, care should be given to symmetrical appearance, weight distribution and crown balance. Cuts should not be made so large that they will prevent normal sap flow.
(11) Periodical drop crotching or cutting back of silver maples, poplars, and other trees with brittle and soft wood that have already been topped or cut back previously may be done again as a means of safety, if determined by the urban forester. However, this method will only be used when there is no other viable arborcultural method that can be used, or in the event of storm damage correction. Damaged trees that require extreme severe drop crotching might have to be removed if the urban forester decides they cannot be salvaged. In addition, trees that have been unlawfully topped severely may be grounds for removal.
(12) An alternate method in some situations for maintaining the safety of these trees would be cabling and bracing as described under that standard.
e. Pruning objectives other than specific pruning classes may be done when there is a specific need for a tree and a full class pruning is unnecessary. In cases where there are specific needs, those needs will be satisfied in the following categories:
(1) Structural: Pruning that influences the orientation, spacing, growth rate, strength of attachment, and ultimate size of branches and stems, resulting in a stronger tree. A solid structure of primary scaffold branches should be established while the tree is young. The scaffold branches provide the framework of the mature tree. Properly trained young trees will develop a strong structure that requires less corrective pruning as they mature. Good pruning techniques remove structurally weak branches while maintaining the natural form of the tree.
(2) Cleaning: Cleaning is the selective removal of dead, diseased, detached, and broken branches. This type of pruning is done to reduce the risk of branches falling from the tree and to reduce the movement of decay, insects, and diseases from dead or dying branches into the reset of the tree. It can be performed on trees of any age but is most common on medium aged and mature trees. Cleaning is the preferred pruning type for mature trees because it does not remove live branches unnecessarily. Cleaning removes branches with cracks that may fail when the interior wood dries.
(A) The location of branches to remove should be specified if the entire crown is not going to be cleaned. The diameter of the branches to be removed also should be specified. This usually is done by specifying the smallest branch to remove (for example, clean branches 1 inch in diameter and larger).
(3) Thinning: Thinning is the selective removal of small, live branches to reduce crown density. Because the majority of small branches are at the outside edge of the crown, thinning is focused in that area. Proper thinning retains crown shape and should provide an even distribution of foliage throughout the crown.
(A) Thinning increases sunlight penetration and air movement through the crown. Increased light and air stimulate and maintain interior foliage, which can encourage taper on scaffold branches. Thinning a limb should be considered if cabling is to be performed. Thinning also can remove suckers from the base of the tree and some water sprouts on the interior. Excessive removal of water sprouts often produces more water sprouts, so it is not recommended. Vigorous production of water sprouts on interior limbs often is a sign of overthinning or lion tailing.
(B) Excessive branch removal on the lower two- thirds (2/3) of a branch or stem (lion tailing) can have adverse effects on the tree and therefore is not an acceptable pruning practice. Lion tailing transfers weight to the ends of branches and may result in sunburned bark tissue, waterspouts, cracks in branches, reduced branch taper, increased load on branch unions, and weakened branch structure. Lion tailing also changes the dynamics of the limb and often results in excessive branch breakage.
(C) If the entire crown will not be thinned, the areas to be thinned must be specified. The size range and percentage of foliage to be removed also must be specified. Usually in the ten (10) to fifteen percent (15%) range, but should not exceed twenty five percent (25%) of the crown, especially on mature trees. Most thinning removes branches one-fourth (1/4) to one inch (1") in diameter. If larger branches are removed, large gaps may be created in the crown or water sprouts can result.
(4) Raising: Raising is the selective removal of branches to provide vertical clearance. Crown raising shortens or removes lower branches of a tree to provide clearance for buildings, signs, vehicles, pedestrians, and vistas. Excessive removal of lower limbs can slow development of trunk taper, can cause cracks or decay in the trunk, and transfers too much weight to the top of the tree. Mature trees could become stressed if large diameter lower branches are removed. Clearance sometimes can be achieved by shortening some of the low branches rather than removing them to prevent these problems. Live crown ratio should be no less than sixty six percent (66%) when raising is completed. Structural pruning should be considered along with raising.
(A) When raising, the desired clearance should be specified. To differentiate between complete branch removal and shortening, specify the size range of the limbs to remove and their location (for example, raise 12 feet about the road by removing downward growing branches 2 inches in diameter and smaller).
(5) Reducing: Reduction is the selective removal of branches and stems to decrease the height and/or spread of a tree or shrub. This type of pruning is done to minimize risk of failure, to reduce height or spread, for utility line clearance, to clear vegetation from buildings or other structures, or to improve the appearance of the plant. Portions of the crown, such as individual limbs, can be reduced to balance the canopy, provide clearance, or reduce likelihood of breakage on limbs with defects. Occasionally, the entire crown is reduced. Reducing or thinning should be considered if cabling is to be performed. Crown reduction should be accomplished with reduction or removal cuts, not heading cuts.
(A) Biologically, reduction cuts are considered less desirable than cuts that remove branches at their points or origin because there is no branch collar or branch protection zone in place when the cut is made to a lateral. Although this concern appears to be minor on small cuts, large cuts on more mature trees may not compartmentalize. Nevertheless, there are circumstances in which reduction is necessary or the best option.
(B) Not all tree and shrub species can be reduced. Therefore, the species and plant health should be considered before starting work. Old, stressed, or mature trees could decline or become more stressed as a result of this treatment. When a limb on a mature tree is cut back to a lateral, no more than one-fourth (1/4) of its foliage should be removed. More can be removed on a young tree to accomplish particular objectives. More decay can enter the tree following reduction than following other pruning types.
(C) The clearance distance or percentage size reduction should be specified. Because making many small cuts or just a few large diameter cuts can reduce a tree, it is important also to specify the size range of cuts. Reduction usually should be done on smaller diameter branches (for example, 1 to 2 inches for trees and 1/2 to 1 inch for shrubs).
(6) Restoring: Restoration is the selective removal of branches, sprouts, and stubs from trees and shrubs that have been topped. Severely headed, vandalized, lion tailed, broken in a storm, or otherwise damaged. The goal of restoration is to improve a tree or shrub's structure, form, or appearance.
(A) On trees with many sprouts originating at the tips of branches, one of three (3) sprouts on main branch stubs are selected to become permanent branches and to reform a more natural appearing crown. To accomplish this objective, consider shortening some sprouts, removing others, and leaving some untouched. Some vigorous sprouts that will remain as branches may need to be shortened to control growth and ensure adequate attachment for the size of the sprout. Lion tailed trees can be restored by allowing sprouts to develop along the interior portion of limbs for one to three (3) years depending on size, age, and condition of the tree. Then remove and shorten some of the sprouts along the entire length of the limbs so that they are evenly distributed and spaced apart. Restoration usually requires several years of pruning.
(B) Specify the location in the tree (for example, top or interior) and the percentage of sprouts to be removed or reduced. Typically, one-third (1/3) of the sprouts are removed and one-third (1/3) are reduced each pruning until adequate branches have developed.
(7) Pollarding: Is the practice of removing all new growth from a tree annually. Although pollarding is associated with topping it is not the same. Pollarding is the cutting back of a limb to a single point on an annual basis. Pruning is done every year and the limbs form a nodule at the point where all new growth is continually removed. However, pollarding even though it is an acceptable practice on some species of trees will not be allowed within Ogden City on publicly owned trees.
(8) Pruning Conifers: Some pruning types are not appropriate for all conifers. For example, branch spacing and scaffold limb development in conifers usually are not necessary. Thinning on spruces and firs rarely is needed. Few conifers respond well to pollarding or reduction. (Eff. 3-14-2007)