Campus Tree Care Policies

Transcription

1 III. Campus Tree Care Policies A. Definition List 1. Branch A secondary shoot or stem arising from one of the main axes (i.e., trunk or leader) of a tree or woody plant. 2. Branch Collar Trunk tissue that forms around the base of a branch between the main stem and the branch or a branch and a lateral. As a branch decreases in vigor or begins to die, the branch collar becomes more pronounced. 3. Callus Undifferentiated tissue formed by the cambium layer around a wound. 4. Crown Cleaning The removal of dead, dying, diseased, crowded, weakly attached, low-vigor branches, and waterspouts from a tree s crown. 5. Crown Thinning The selective removal of branches to increase light penetration and air movement and to reduce weight. 6. Girdling Roots Roots located above or below ground whose circular growth around the base of the trunk or over individual roots applies pressure to the bark area, ultimately restricting sap flow and trunk/root growth, frequently resulting in reduced vitality or stability of the plant. 7. Heading (Lopping/Stubbing /Topping) Cutting a currently growing or one-year-old shoot back to a bud, or cutting an older branch or stem back to a stub or lateral branch not sufficiently large enough to assume the terminal role. Heading should rarely be used on mature trees. 1. Leader A dominant upright stem, usually the main trunk. There can be several leaders in one tree. 8. Mulching placing organic shredded hardwood around the base of a tree to protect roots and bark from mower/trimmer damage and reduce weed growth. A better alternative would be to grow ground cover under trees that will blend with grass without encroaching into the turf. Keep mulch at least 18 from the truck and no more than 3 inches deep. 2. Precut or Precutting The two-step process to remove a branch before the finished cut is made so as to prevent splitting or bark tearing into the parent stem. The branch is first undercut, then cut from the top before the final cut. A total of three cuts is needed to completely remove the branch.

2 3. Raising Removing lower branches to provide clearance for thoroughfares, street lights and structures. Always keep live branches on at least 2/3 of tree s total height. 9. Reduction Use only when absolutely necessary to reduce overall height of tree or length of individual branch. Cut at lateral that is at least 1/3 diameter of stem being removed. If more than half foliage is removed, remove entire branch. 10. Stub An undesirable short length of a branch remaining after a break or incorrect pruning cut is made. 11. Thinning The removal of a lateral branch at its point of origin or the shortening of a branch or stem by cutting to a lateral large enough to assume the terminal role. 12. Tracing Shaping a wound by removing loose bark from in and around a wound. *More definitions can be found in Appendix N ANSI A300 B. General Planting Practices 1. TREE FARMS Layout and Planting a) We currently manage eight separate tree farms on outlying properties and adjacent to the Grounds Facility with the assistance of a tree farm maintenance contractor. We have a complete inventory of these trees by size and species. This inventory should be revised on an ongoing basis as new trees are planted and others are transplanted to campus. b) We plan to add an additional one to two tree farm plots each year to create a green belt around the north and east of campus and provide canopy for future development. c) The tree rows are staggered, with trees spaced feet apart and 10 feet of mowed turf between rows. This allows our mowing contractor for lots to keep the area weed free and within city code requirements. d) Species are varied, and arranged by size and form appropriately, to include conifers and ornamental trees where height restrictions exist. e) Our long term goal is to never purchase a tree larger than 1 caliper, as transplanting by spade on campus guarantees a much higher success rate for quick canopy.

3 f) These trees will be used not only to replace trees on campus, but also made available as memorial trees, with the customer covering the transplanting costs only. 2. MACHINE DUG TREE (Tree Spade) SPECIFICATION a) General Condition (1) Strict adherence to ISU s Machine Dug Tree Tree Spade Specification will be enforced. The tree spade contractor shall comply with the subsequent conditions and methods during the designated tree relocation process. b) Indiana State University will flag the designated tree specimen or specimens for digging and relocation. Generally, trees are moved within the confines of ISU properties. The Indiana State University Grounds Maintenance Division will be plans or by staking or by site visit with the tree spade contractor designate the new location for moved tree or trees. c) The contractor shall spray foliaged trees with an approved ANSI Nursery (latest edition) anti-transpirant before digging the specimen. Anti-transpirants shall be applied to both sides of the leaves. The contractor shall spray a second application of the anti-transpirant three days after the specimen has been relocated. Application rates shall be in accordance with the manufacturer s directions. d) Before the tree specimen is dug, the same tree spade machine shall be used at the planting site for the excavation of the planting hole. The contractor shall assure that the soil in the bottom of the excavation sire if firm enough to prevent excessive settling of the spe-cimen once it is placed in this hole. If needed the contractor shall provide and install addi-tional soils as necessary to the excavation pit for the correction of any excessive settling problems. e) The contractor shall take adequate precautions to prevent damage to existing sidewalks, pavers and curbs by way of load distribution pads and similar methods and means. f) The contractor shall conduct a visual inspection of all specimens that are flagged for relocation. This inspection will consist of measuring the caliper of the tree at 4.5 feet above existing grade and the providing the appropriate tree spade per the following table (No exceptions shall be allowed for the Minimum Diameter Root Ball Size) 3. HOLDING AREA TREE CARE

4 a) Taking delivery of trees to be planted on campus within 10 days requires they be arranged and spaced for ease of access and not touching one another. They should be watered daily, especially if in black plastic containers. b) If trees will remain in the holding area longer than 10 days, they should be mulched heavily. If they are to remain over the winter (which should be avoided at all costs) they should be trenched to a depth equaling half the root ball height, and then mulched thoroughly. They should be watered until the grounds is completely frozen, as winter drought is devastating to trees without adequate root structure. c) Storing trees in the holding area will decrease as our tree farms gain size and we need to purchase less and less trees over 1 caliper. 4. TREE CIRCLE AND RIGHT OF WAY MAINTENANCE a) In the past, tree circles have been shaped and maintained using Round Up. This is no longer considered an acceptable practice. Research has shown the surfactants in Round Up affect a tree s ability to move nutrients through the cambium layer. After years of treatment in the root zone, the bark can even separate from the tree. We have examples of this on campus. b) As tree circles are mulched, weeds should be hand pulled or scraped with a hoe. Mulch should be no deeper than 3 inches, old hardened mulch layers should be removed, and no mulch should be placed within 4-12 inches of the tree trunk, depending on its caliper. c) Trees in the tree row, where turf is present, should be square in shape, with two straight lines, the curb and the sidewalk forming the four sides of the square. This allows us to maintain a clean edge between turf and mulch, and keeps mowers off the CRZ. 5. HAZARD TREE INVENTORY a) A Hazard Tree Inventory will be performed in every even year. Our contracted certified Arborist performed the first inventory of this kind in It was his first inventory, and wasn t as useable and functional as it could have been. As we complete the main Tree Inventory for campus, performing the hazard inventory will be easily accomplished using the JUNO GPS device. This will allow us to print lists from ArcMap, detailing the types and priority of necessary pruning activities.

5 b) As this inventory is accomplished in the summer of the even year, deadlines will be established for pruning activities based on priority, and assigned to our contracted tree service, or to each gardener if it can be accomplished in house. 6. STORM DAMAGE CLEARANCE AND TREATMENT a) Facilities maintains a current list of contact numbers for responsible authorities, which includes storm damage. Our Lead Gardener is listed. When he is not available, a responsible person will be designated, such as the senior Gardener on staff. (See Appendix E) b) Fallen Limbs obstructing roadways, major pedestrian pathways, or entrances to buildings must be cleared within 2-4 hours of discovery weather permitting, and necessitate a call back if occurring outside regular work hours. Usually, the garden crew for that specific area will be called, unless the size of the limb necessitates the use of equipment, in which case one or two GEO s will be called in as well. c) The first stages of response involve removal of all limbs or branches causing safety concerns. If these branches are still connected to the tree, they should be separated at the break point, using the safest technique for the particular situation. Any cut that cannot be made from Ground Level will require the involvement of our Tree Service, as we are not authorized to make any cuts from a ladder or truck bed. Follow-up cuts can be made by our Lead Gardener, Certified Arborist, or Gardener after the health and viability of the tree have been examined and determined. d) If using a chain saw, all proper safety equipment should be worn, and safe use practices should be observed. Only those trained and authorized to use a chain saw can operate them. In other words, storm damage is not a good time to train someone on equipment they are not familiar with. (See Appendix C) 7. INTEGRATED PEST AND DISEASE MGT AND TREE FERTILIZATION CALENDAR a) All ISU Gardeners are Indiana State Pesticide Applicator certified. They participate in ongoing educational seminars to maintain this certification. b) Purdue University is an invaluable resource to our Gardeners in learning to manage pests and diseases at minimal cost and without causing further environmental damage or unintended side effects.

6 c) The Lead Gardener is responsible for ensuring all Gardeners maintain their certifications, and for the training of new gardeners. d) ISU Grounds will promote a basic philosophy of caring for the soil, water, and air quality needs of trees in order to prevent pests and diseases from gaining a foothold. This can be defined as a Prevention Policy. e) When species specific problems occur that threaten a large number of trees on campus, every effort will be made to diagnose and treat and prevent spread, within budgetary limits. f) Specimen trees may receive a higher level of treatment and attention, or a greater monetary investment, as determined by the Grounds Manager, or higher in the chain of command. g) A library of manuals and books is maintained in the conference room, a library of dvd s in the training room, and a list of useful web links on the web site. Every opportunity is exploited to assist in the training and background knowledge of ISU s Grounds Gardeners. C. Structural Pruning & Tree Care 1. How to Prune Young Shade Trees a) At Planting Time: (1) Very little should be done to a young shade tree. It is best to leave as many leaves on the tree as possible. This will help to manufacture food which will help to build a larger root system. Broken branches should be removed either partially or completely. If there are two leaders, remove one. b) After 3-4 Years: (1) By the time that a tree has been in its new home for 2 to 4 growing seasons, it is time to do some more pruning. (2) Cut off any suckers that originate from the roots and sprouts in the crown. Root suckers sap strength from the tree. Sprouts can become disprportionally vigorous and are weakly attached tot the tree. If they are left, they will become weak limbs which are subject to damage later in the trees life. (3) Remove or thin other excessive branches to reduce competition forlight, water and nutrients and remove any codominant leaders.

7 D. Tree Removal (4) A few of the lowest limbs can be removed, but leave others on temporarily to help the trunk develop more taper and strength. (5) Check for other problem areas such as branches that rub or are growing in an undesirable direction. (6) Eliminate narrow angles. (7) Try not to remove any more than 1/3 of the total leaf surface in one pruning. c) After 5-7 years: (1) Continue to remove root suckers and sprouts in the crown. (2) Lower limbs are pruned off to raise the bottom of the crown. In some cases, high enough for vehicular traffic, pedestrian traffic, or sign clearance. The lowest limbs now will become the permanent lowest limbs. (3) Some cutting back can be done on the crown at this time. (4) For more even spacing, a few branches here or there can be removed d) After 7 years: (1) Continue to remove root suckers and sprouts in the crown. (2) Continue to check the tree periodically for dead or damage limbs and remove them with proper pruning techniques. 1. Live trees should only be removed when more than 2/3 dead, when a public hazard is present, when they are of undesirable species (invasive), or when new construction plans have exhausted every possibility of saving them. 2. Trees of 10 caliper of less should be transplanted whenever feasible. 3. Diseased trees require consultation with the contracted Certified Campus Arborist, whose recommendations will be followed 4. Trees will never be painted with large X marks in advance of their removal anywhere on campus. Use of ribbon or mapping is preferable. 5. When significant trees or large numbers of trees are to be removed, a public statement through campus media channels will be released explaining the justification and schedule.