2_Exhibits A, C & D - Laserfiche WebLink

Guide to Care of California Native Oaks NortScience,Inc. Page 4 Fertilization Oaks do not normally require annual fertilization if the leaf litter is allowed to accumulate under the canopy. As the leaves decompose, they return nutrient elements to the trees. If you routinely remove the natural leaf litter,then plan to fertilize your oak every two to three years. A slow-release fertilizer that provides only nitrogen is the best material to use. Apply the material at a rate of 1 pound actual nitrogen per 1000 ft'of open soil under the dripline plus 10' beyond. Spread the fertilizer evenly on the soil within the dripline of the tree plus 10' beyond (where possible). Apply in the late winter before the rains end. Mulching Oaks benefit from a layer of thick organic mulch beneath the canopy. The mulch helps retain surface soil moisture, moderates temperatures, and provides nutrients for the tree as it decomposes. Mulch material can be purchased at garden centers. You can also have brush from prunings chipped and left under the trees. Allow the natural leaf litter to accumulate within the mulched area as well. Mulch should be maintained at a maximum thickness of 4-6". Pest Management Coast live oaks rarely need treatment for pest problems. Insects such as oak moth and galls do not adversely affect tree health and do not require treatment. rees on slopes, soaker berms to create watering hoses placed in concentric rings basins around trees on flat can be used to provide ground. An inner berm keeps supplemental water. Mulch can be water away from the trunk. placed over the hoses. ore 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