(A) The landscape plan shall incorporate species diversity. Any proposed use of a monoculture will require county approval.
(B) Requirements for species diversity. A site that requires more than 15 PU shall provide plantings to create diversity at the following minimum percentages: 20% species and 25% genus. These percentages apply to major and minor deciduous trees and evergreen trees.
(C) Plant quantity requirements. Minimum required plant quantities shall be based on PUs. Caliper size shall be in accordance with ANLA standards. One PU equals:
(1) One major deciduous tree at least one and one-half inches in caliper at installation;
(2) Two minor deciduous trees one inch in caliper at installation;
(3) Two evergreen trees at least five feet in height at installation;
(4) Five shrubs, 18 inches in height at installation depending on screen type;
(5) Five hundred square feet of groundcover at recommended ANLA standards;
(6) Ten herbaceous or perennial plants at one-gallon size may only be used to meet Class D screening, as set forth in this chapter; and
(7) Twenty herbaceous or perennial plants at one-quart size may only be used to meet Class D screening, as set forth in this chapter.
(D) Screening.
(1) General requirements.
(a) Screening is required to diminish the impact of undesirable views and mitigate the visual conflict and other effects (noise, fumes, and light spillover) of adjacent dissimilar land uses. Screening shall consist of trees and shrubs, fences, berms in conjunction with planting materials, solid brick or architectural block walls. The degree of intensity of adjacent land uses and width of landscape strip available as a buffer will dictate the height, density, opacity, and landscape elements required.
(b) Screening is required for nonresidential uses adjacent to residential zones or uses, dumpsters, storage and loading areas, service lanes, parking lots, and other conditions as required.
(c) A minimum ten-foot wide landscape strip is required to accommodate screen planting unless otherwise stated in this chapter or the Manual.
(d) Screening may be waived in whole or in part by the county provided the developer can demonstrate that adequate and perpetual screening exists on an adjacent property.
(2) Screen types.
(a) Class A.
1. The function of Class A is to provide a visual screen that will give the required level of height, density, and opacity depending on site conditions. The screen may range from a solid linear screen of evergreen trees where maximum opacity is needed to a loosely staggered screen where a filtered view is appropriate, based on site conditions. A combination of major deciduous trees, minor deciduous trees, evergreen trees, and shrubs may be used.
2. Minimum size at installation shall be 18 inches for shrubs and five feet for evergreen trees.
3. A six-foot high opaque fence or wall may be required in conjunction with a planting screen.
4. PUs shall be generated at one PU per 20 linear feet of the area to be screened.
(b) Class B.
1. The function of Class B is to screen parking lots and service lanes while maintaining views into the site.
2. Minimum height of shrubs at installation shall be 18 inches. Shrubs must provide a minimum three-foot high year-round visual screen at maturity.
3. A three-foot high solid fence or wall may be required in conjunction with planting screen.
4. PUs shall be generated at one PU per 20 linear feet of the area to be screened.
(c) Class C.
1. The function of Class C area is to provide a spatial and vegetative buffer between single-family residences and other uses.
2. Where screening is required, a minimum 15-foot buffer shall be established. A minimum of 30% of the required PUs shall be evergreen trees and a minimum of 50% shall be major deciduous trees.
3. PUs shall be generated at one PU per 15 linear feet of area to be screened.
4. The use of a planting scheme reflective of the natural state landscape is required for proposed plantings.
5. Existing tree canopy coverage may be approved as credit toward this requirement based on the size and condition of the existing tree canopy.
(d) Class D.
1. The function of Class D is to provide low level planting to give visual relief from paved areas while maintaining the view of outside display areas. Street trees combined with a Class D screen provide continuity of streetscape. Mature planting shall be a minimum of 24 inches in height, measured from the top of curb of the adjacent road. A combination of mature (two years after planting) plant height and berm height may be used to achieve the minimum height. Herbaceous plants may be used at recommended ANLA standards.
2. Class D screen may also be satisfied by increasing the landscape setback to 15 feet and providing a 24-inch minimum height grassed berm along the length of the display area.
3. PUs shall be generated at one PU per 25 linear feet of display area adjacent to the public right-of-way.
(E) Fence specifications.
(1) For board-on-board fences, the minimum wood panel thickness shall be one-half inch. The minimum frame size shall be two inches by four inches and minimum post size shall be four inches by four inches.
(2) Fences or walls shall be constructed of durable, low maintenance materials coordinated with the materials used on building facades.
(3) Fencing or walls shall be placed on the inside edge of the landscape strip with planting on the residential or street side of the fence or, in wider buffers, placed to allow planting on both sides of the fence. Fencing shall be located at the grade elevation that achieves the required screening.
(4) Security fencing along a public right-of-way may not be placed in a county right-of-way and shall be set back ten feet to allow planting on the street side of the fence.
(5) Proposed grades, fence location, and construction detail are required on the landscape plan.
(F) Credit for preservation and conservation of existing trees.
(1) Credit may be given for the preservation of major trees existing within the buildable area of a development site when they are in a location and of a nature that they contribute to the purpose and objectives of this chapter. A credit of two PUs shall be given for each major tree three inches or greater in caliper if the tree is healthy and in good condition and form as determined by the county. The identification of trees proposed for conservation shall be shown on the preliminary plan of subdivision or site plan and identified in a table included on the plan that outlines the location of the trees, their species, size and condition. A determination of final credit to be given will follow field verification of the listed data. The final landscape plan shall include landscape tree protection measures.
(3) Trees proposed for conservation shall be native species or noninvasive, nonnative species appropriate for inclusion in their new setting. Credit may not be given for unacceptable species as listed in the Manual. Trees shall also be in good health and free from pests that would compromise their survivability. Trees shall also be in a location that will enhance the ultimate landscape of the development. The following conservation standards shall be adhered to.
(a) The critical root zone of trees designated for preservation shall be protected from disturbance and compaction.
(b) Other conservation measures may also be warranted, i.e., root pruning, crown reduction, etc., if conditions dictate and the value of the conservation is greater than the value of the measures to be undertaken.
(c) Isolated trees shall be protected with individual measures. Groups of trees may be encircled as they stand to a point approximating the critical root zone of the outermost tree.
(d) The relocation of individual trees may be appropriate under circumstances if the tree can be moved and replanted with a high probability of survival.
(e) If trees are to be relocated an individual maintenance plan designed to assist the tree in survival is required.
(f) Trees to be preserved shall be marked in the field and tree protection measures shall be installed prior to the issuance of grading permit for the site.
(g) A construction sequence, which includes installation and removal of protective measures and any necessary maintenance, shall be submitted prior to final approval.
(h) Appropriate corrective action shall be taken when trees are inadvertently damaged. If it is determined that any part of a tree is in an unsafe or dangerous condition, then that part of the tree shall be removed. If the entire tree is affected, it shall be removed in its entirety. If the hazardous condition is questionable, then the property owner shall employ a certified arborist to inspect the tree and certify that the condition of the tree is not a hazard and is not expected to be a hazard in the foreseeable future. Damaged trees that require removal may not be credited toward any required PUs.
(i) In accordance with § 157.21, the replacement value of the conserved trees shall be bonded in an amount equal to the number of planting unit credits for a period of one year from the initial inspection as determined by the county. Trees that exhibit postconstruction stress at that time may require replacement with the equivalent PUs.
(G) Unacceptable species. Species which may not be used in the landscape design are listed in the Manual.
(H) Landscape plan preparation. All landscape plans shall be prepared by a:
(1) Licensed landscape architect; or
(2) Qualified landscape designer:
(a) Having a degree or certificate from a recognized program in horticulture, landscape design or a related field, and having two years experience preparing plans and landscape construction drawings; or
(b) Having five years experience in preparing planting plans and landscape construction drawings.
(I) Plan review and approval. Landscape plan requirements shall be satisfied prior to Planning Commission approval. Placement of plant materials shall conform to the requirements contained in the Manual.
(J) Installation.
(1) Standards to conform to the most recent version of the ANSI A300 Standards, Part 6 – Transplanting and Landscape Specifications Guidelines of the Landscape Contractors Association, Maryland, District of Columbia and Virginia.
(2) Planting on individual lots shall be installed upon final grading inspection. No final grading approval shall be given on the building permit until landscaping is complete.
(K) Maintenance responsibility. The owner of any property on which landscaping has been installed pursuant to this chapter shall maintain the landscaping in good condition in perpetuity. A landscape maintenance agreement shall be required. Failure to replace dead or dying PUs or the removal of any installed PUs is a violation of this chapter.
(L) Variances.
(1) The county may grant a variance to any of the technical requirements included in this chapter in accordance with this section, if there are exceptional circumstances that could result in one or more of the following conditions:
(a) Strict adherence could result in an unnecessary hardship or a condition contrary to the intent of any individual technical standard;
(b) Where varying the standard would result in enhanced environmental benefit;
(c) Adherence to the standard would compromise the general intent of this chapter and the Manual;
(d) Where adherence to the standard would detract from the existing streetline character; or
(e) It can be proven that adherence to the technical requirement would not be necessary to fulfill the purpose of this chapter.
(2) A written request for any variance shall be submitted to the county for review and approval. The request shall state the specific variance sought and the reasons supporting the request. An applicant for a variance shall include the following:
(a) A description that special conditions or exceptional circumstances peculiar to the site or setting exist that would cause undue hardship or would contradict the specific standard that is the subject of the variance request;
(b) A demonstration, in sufficient detail, that the granting of the variance will not confer on the applicant any special privilege that would be denied other similar submittals;
(c) A demonstration that the variance request is not based on conditions or circumstances resulting from actions by the applicant; and
(d) A demonstration that the request, if granted, will not impair environmental quality or result in any form of degradation.
(3) For any development located within an incorporated municipality, a notice of a request for a variance to this chapter will be forwarded by the applicant to the Mayor of that municipality. Proof of submittal to the municipality shall be provided to the county.
(4) In granting a variance to this chapter, the county shall issue written findings of fact that the applicant has met the requirements of the above divisions (L)(1), (L)(2), and (L)(3) and that granting the variance is consistent with the intent of this chapter.
(M) Inspections. A minimum of two inspections will be required. No inspections shall be finalized from November 1 to March 1. To be considered acceptable, no more than one-third of a plant may be dead.
(1) Initial inspection. This inspection shall be performed by the county when planting is completed to verify compliance with the approved planting plan.
(2) Final inspection. This inspection shall be performed by the county 12 months after the initial planting.
(N) Overlap. Where planting unit requirements on a single site overlap or are immediately contiguous, credit for one planting requirement may be applied to the other requirement.
(2004 Code, § 134-6) (Ord. 04-23, passed 11-4-2004; Ord. 2011-03, passed 5-17-2011; Ord. 2013-02, passed 3-21-2013)