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20978 Fairwoods Ct_TRA report_Cupertino_Dec 2024 HortScience│Bartlett Consulting ● Divisions of The F.A. Bartlett Tree Expert Company 2550 Ninth Street Suite 112 ● Berkeley, CA 94710 ● 925.484.0211 ● www.hortscience.com December 19, 2024 Emi Sugiyama City of Cupertino 10300 Toree Avenue Cupertino, CA 95014 Subject: Deodar cedars 20978 Fairwoods Ct. Dear Ms. Sugiyama: You requested that I assess the health and structural condition of two mature deodar cedar (Cedrus deodara) trees located on private property at the subject location. I inspected the trees on December 6. I met with Mr. Roddy Chan who has owned and occupied the property for approximately 40 years. On October 13, 2024, Mr. Chan applied for a permit to remove both trees. The City of Cupertino requested an arborist report with risk assessment to evaluate the health of the trees and risk of failure. This letter summarizes my observations and assessment. Observations Deodar cedar #100 was 29 inches in diameter and in fair condition. The tree was located in an elevated trapezoidal bulb-out which extended approx. 6 feet from the west boundary wall. The bulb-out is 3 feet high and encompasses the tree on three sides by 1 and 2 feet (Photo 1). It is part of a raised planter which extends 2 feet from the boundary wall and runs to the north property line. Mr. Chan stated that he installed the raised planter 35 years ago. The tree had been growing at grade level and was preserved through the construction of the residence. Three (3) feet of soil filled the void between the trunk and planter walls and buried the root collar. The tree exhibited a slight sweep to the east with multiple attachments arising at 25 feet. A 14-inch lateral limb emerged north at a 90-degree angle 15 feet above grade. Form and structure were typical for the species and attachments appeared normal. Vigor was moderate with somewhat sparse foliage and minor dieback of 1 – 2-inch diameter branches. Branches on the east had been raised and reduced away from the house. Branches in the rest of the crown had not been regularly pruned and were overextended to the north and west into the neighboring property. Photo 1: Deodar cedar #100 was located in a raised planter which buried the root collar. TR-2024-041 4/15/2025 Emi Sugiyama City of Cupertino, Risk Assessment December 2024 20978 Fairwoods Court, Cupertino Page 2 HortScience│Bartlett Consulting ● Divisions of The F.A. Bartlett Tree Expert Company Soil had been excavated 6 inches from the outer retaining wall in 2023. Adventitious roots were removed from this area to an undetermined depth. Soil had partially backfilled this area to a point 6 inches below existing grade (Photo 2). Sap was observed on the north side of the trunk from base to 6 feet but did not appear related to a fungal disease, infection, or insect damage. Sounding around the base of the trunk with a hammer did not reveal potential cavities or decay. Cedar #101 was in fair condition with a trunk diameter of 27 inches. The tree was located in an elevated hexagonal bulb-out which extended approximately 6 feet from the west boundary wall. The bulb-out was 3 feet high and surrounded the tree by 2 and 3 feet (Photo 3). The tree had been growing at grade level and was preserved through the construction of the residence. Three feet of soil filled the void between the trunk and planter walls and buried the root collar. The tree bowed south and leaned slightly west towards the neighboring residence. Form and structure were typical of the species and attachments appeared normal. Foliage was sparse and gaps were extensive through the south side of the crown (Photo 4). Photo 4: Branches and foliage were sparse on the south side of the crown. Photo 2: Soil partially backfilled the space between tree #101 and planter walls. Photo 3: Tree #101 was located in a raised planter and had a buried root collar. TR-2024-041 4/15/2025 Emi Sugiyama City of Cupertino, Risk Assessment December 2024 20978 Fairwoods Court, Cupertino Page 3 HortScience│Bartlett Consulting ● Divisions of The F.A. Bartlett Tree Expert Company Overall, vigor was moderate with somewhat sparse foliage and minor dieback of 1 – 3-inch branches. East laterals were raised and headed away from the house. A 14-inch lateral limb emerged west at an 80-degree angle 15 feet above grade. It had a wound caused by a rubbing 3-inch branch at 25 feet (Photo 5). Branches in the rest of the crown had not been regularly pruned and were overextended to the south and west over the neighboring property. In 2023, soil had been excavated approx. 1 foot from the outer retaining wall to repair cracks. Adventitious roots were removed from this area to an undetermined depth. Soil had been loosely backfilled to grade level. A loose bark plate was removed from the east base of the trunk. It revealed a white substance which appeared to be dried sap and not related to a fungal disease (Photo 6 and inset). Sounding around the base of the trunk with a hammer did not reveal potential cavities or decay. Photo 5: A crossing branch had rubbed a wound into a large upright lateral limb. Photo 6 and inset: A loose bark plate did not reveal fungal disease. TR-2024-041 4/15/2025 Emi Sugiyama City of Cupertino, Risk Assessment December 2024 20978 Fairwoods Court, Cupertino Page 4 HortScience│Bartlett Consulting ● Divisions of The F.A. Bartlett Tree Expert Company Response to City of Cupertino Questions On November 7, the City of Cupertino requested that we address the following items: 1. Based on your assessment, do you see any evidence that the health of the Deodar Cedars may be declining? Are these trees at risk of falling? Both trees were in fair condition at the time of assessment. Tree condition appeared to be good in Google Street View photos taken in 2011. This suggests tree health is declining. We cannot know whether the trees are at risk of falling without examining the base of the trees. Three feet of soil obscured the base of each tree which prevented an assessment of the base and root collar. Overextended branches growing into the neighboring property are more likely to fail than pruned branches on the client side. 2. Do the trees have good structure? Are the branches overhanging the residence large enough to pose a risk of damage to the roof? Would removing a leader or specific branches minimize the danger of falling branches, or are there still large leaders that can cause potential damage to the residence? Both trees had good structure. Form was asymmetric due to branches on the owner’s side having been reduced in length over the years, while branches were left unpruned on the neighbor’s side. Consequently, no branches overhung the owner’s residence, yet branches were long and extended into the neighboring property to the west. Branches which overhung the neighboring residence were not large enough to cause significant damage to the roof should they fail. The main leaders which comprised the structure of each tree appeared to be well- attached. There was no indication from the ground that any of the leaders would fail under normal conditions. A 14-inch upright lateral on tree #101 had a wound at 25 feet on the west (neighbor’s) side caused by a rubbing branch. Removing or reducing this lateral would mitigate the risk of it failing onto the neighboring property. 3. In your opinion, does the proposal to remove the trees meet at least one of the criteria for removal in the City of Cupertino’s Municipal Code? 14.18.180 Review, Determination and Findings. A. The approval authority shall approve a tree removal permit only after making at least one of the following findings: 1. That the tree or trees are irreversibly diseased, are in danger of falling, can cause potential damage to existing or proposed essential structures, or interferes with private on-site utility services and cannot be controlled or remedied through reasonable relocation or modification of the structure or utility services; This criterion was not met. 2. That the location of the trees restricts the economic enjoyment of the property by severely limiting the use of property in a manner not typically experienced by owners of similarly zoned and situated property, and the applicant has demonstrated to the satisfaction of the approval authority that there are no reasonable alternatives to preserve the tree(s). This criterion was not met. TR-2024-041 4/15/2025 Emi Sugiyama City of Cupertino, Risk Assessment December 2024 20978 Fairwoods Court, Cupertino Page 5 HortScience│Bartlett Consulting ● Divisions of The F.A. Bartlett Tree Expert Company 3. That the protected tree(s) are a detriment to the subject property and cannot be adequately supported according to good urban forestry practices due to the overplanting or overcrowding of trees on the subject property. This criterion appears to be met based on the 3-foot retaining wall and fill soil which surrounded each tree for more than 30 years. Trees grew in a narrow, raised planter within close proximity to two occupied homes. Trees are too large to adequately reduce away from homes without damaging trees, and tree health appears to be declining. 4. If the trees were removed, what would be adequate replacement? The City typically requires that the replacement trees be a California native species that is similar in size to the tree that was removed. Is there room on this lot for two upper-canopy trees, or should at least one of the trees be lower-canopy and non-native, or are there no locations with sufficient space for upper-canopy trees. Can you provide recommendations for replacement tree species for both trees? There is no room on this lot for two large-canopy trees. One large-canopy and one small- canopy tree would be adequate. Appropriate native trees for this location are limited. Suitable replacement trees include, but are not limited to: - Cook pine (Araucaria columnaris), Non-native - Marina madrone (Arbutus ‘Marina’), Possible native/non-native hybrid - Italian cypress (Cupressus sempervirens), Non-native - Coast silktassel (Garrya eliptica), Native - Sweetshade (Hymenosporum flavum), Non-native - Avocado (Persea americana), Non-native / Naturalized - Water gum (Tristaniopsis laurina), Non-native - Island oak (Quercus tomentella), Native 5. Do you have any suggestions or concerns with the removal or replacement overall? Tree health is likely in decline due to base of trees being buried under 3 feet of soil for over 30 years. This may also adversely affect tree stability. Removing the raised planter will allow for inspection of tree bases, and may improve tree health. Other than Italian cypress and coast silktassel, trees listed above should not be grown in raised planters. TR-2024-041 4/15/2025 Emi Sugiyama City of Cupertino, Risk Assessment December 2024 20978 Fairwoods Court, Cupertino Page 6 HortScience│Bartlett Consulting ● Divisions of The F.A. Bartlett Tree Expert Company Discussion and Recommendations Deodar cedars #100 and 101 were preserved when the residential property was built. The trees were in the rear yard, 2 feet from the masonry wall which forms the property line. Thirty-five years ago, a 3-foot planter was added, surrounding the tree trunks and burying the base in 3 feet of fill soil. I was unable to observe the original base of trunk which should be at the level of existing ground. The planter had been irrigated for approximately 25 years but the irrigation was capped 10 years ago. In 2023, soil was removed from between the walls and trees. Roots were severed and soil was loosely filled back into the voids. Both trees were sounded around the base with a hammer and sap exudate was observed on the trunk of tree #100. A loose bark plate was removed from tree #101 and examined. No mycelial plates, fungi, or insect activity were observed. Attachments in the upper crown appeared normal, making it unlikely that any stems would fail under normal conditions. I compared photos of the trees taken in 2024 (Photo 7) with those taken in 2011 (Photo 8). Tree crowns appeared to be thinner suggesting that overall tree health has declined over the last decade. This is likely due to the long-term effect of the fill soil or removal of irrigation? on tree root growth as I did not find any disease or insect pests in either tree. Photo 8: Subject deodar cedars in good condition in March 2011. Note the pine tree at left which has since been removed. (Photo via Google Street View) Photo 7: Deodar cedars #100(R) and 101(L) in fair condition in December 2024. TR-2024-041 4/15/2025 Emi Sugiyama City of Cupertino, Risk Assessment December 2024 20978 Fairwoods Court, Cupertino Page 7 HortScience│Bartlett Consulting ● Divisions of The F.A. Bartlett Tree Expert Company Although large, mature trees are visually and emotionally appealing, they can present significant maintenance and safety problems as they age. To assist City personnel in their decision-making process, options for future tree management follow. Based on my observations, there are at least three management options for trees #100 and 101: 1. Retain and monitor. The trees appear generally normal in development save for the history of pruning. There were no indications that whole tree failure is likely. If branches on the neighbor’s property are problematic, they can be pruned. I recommend annual inspections by a qualified arborist and inspections after large storm events. 2. Retain and prune by reducing the size of crown. Prune to reduce the length of live overextended branches and remove dead and dying branches. For tree #101, reduce the damaged 14-inch limb to an established lateral branch just above the wound. This will reduce the likelihood of branch failure. The trees should be inspected 1 year after pruning to assess any new dieback. 3. Remove the trees now. If you would like to eliminate the risk associated with the possibility that a whole tree failure would damage either house, then remove the trees. The tree owner clearly does not want branches to extend over his roof. Please feel free to contact me with any questions regarding my findings. Sincerely, HortScience | Bartlett Consulting Scott Wheeler, Consulting Arborist ISA Board Certified Master Arborist #WE-10187B ISA Tree Risk Assessment Qualified TR-2024-041 4/15/2025 Emi Sugiyama