2_Exhibits A, C & D - Laserfiche WebLink

Guide to Care of California Native Oaks HortScience,Inc. Page 2 existing oaks. Only infrequent irrigation (once a month, maximum) is compatible with oaks. 5. If lawns or other frequently irrigated planting are to be used, place them outside the driplines of oaks. 6. When planning landscape irrigation, route all irrigation trenches outside the driplines of oaks. Make sure that the area within 10' of the trunk is not wetted during operation of the system. Also, direct runoff away from oaks. Maintenance of Oaks in the Landscape Native oaks have survived for decades in a system that provides the right balance of water, elements, light, etc. Even though we try to design appropriately around oaks, the balance that nature has provided is interrupted. The trees become a maintenance responsibility. The primary maintenance requirements of oaks are pruning, mulching, pest and disease control, and in some cases, irrigation and fertilization. Pruning Mature oaks seldom need much pruning. It is important to maintain as much foliage as possible to supply the tree with adequate food for growth and maintenance. Your trees were pruned prior to the start of construction. Oaks are pruned to enhance their health and structural stability, and to provide clearance beneath their crowns. Removal of dead, dying, diseased and weak branches enhances tree health and reduces the potential for failure of a branch. Topping and stubbing off branches are not appropriate pruning methods for any tree, particularly oaks. Avoid stripping out the interior foliage. Excessive pruning to expose the branch structure of oaks is very damaging. As a general guide, remove no more than 25% of the foliage of the tree. Previously shaded branches that are exposed to the sun are easily damaged from sunburn. Pruning to reduce the weight on heavy horizontal limbs should remove small diameter branches (less than 3"), and retain foliage along the length of the branch. Trees need to be inspected annually to evaluate structural stability and need for pruning. Most old oaks have considerable amount of decay in the trunk and major branches. They need to be inspected regularly by a professional to determine if weight needs to be removed from weak areas to reduce the risk of branch or trunk failure. Pruning and cabling should be undertaken by qualified arborist. Tree pruning companies must carry the California State Contractors License for Tree Services (#C61/D49). Any pruning should be performed by a Certified Arborist or Tree Worker and adhere to the Tree Pruning Guidelines of the International Society of Arboriculture. Irrigation irrigation per month). No plants should be installed within 10' of the trunk of the tree. A list of species appropriate for use under oaks is listed in Table 1. 4. Irrigation systems must be very carefully designed to avoid trenching through roots. No irrigation lines shall be placed under the driplines of HortScience,Inc E 325 Ray St. I Pleasanton, CA 94566 phone 925.484.0211 I fax 925.484.50961 www.hortscience.Com ll not be placed within the TREE PROTECTION ZONE, either temporarily or permanently. Any modifications must be approved and monitored by the Consulting Arborist. 2. All demolition, excavation and construction within the dripline of trees shall be done using the smallest equipment possible. The Consulting Arborist will identify where hand excavation may be required. Motorized equipment shall not be used within the TREE PROTECTION ZONE. 3. Prior to excavation for the demolition and construction the tree may require root pruning outside the TREE PROTECTION ZONE by cutting all roots cleanly to the depth of construction. Roots will be exposed by either: pulling soil away from the tree by digging , normally 54"above grade. A multi-branched tree, which has