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2016 Draft Landscaping Code <br />18.52.70 Soil Preparation, Planting and Irrigation <br />A. Soil Preparation and Planting <br />1. For landscaping in sidewalks and parking lots, or in limited areas of �soill volume, <br />Commented [CL74]: 18.28.240 B.3. <br />structural soils (Cornell University product or similar) must be used to a preferred depth of <br />36 inches, to promote tree root growth and provide structural support to the paved area. <br />Minimum soil volumes for tree roots shall be 750 cubic feet per tree (see specifications <br />and sample plans for CU- Structural Soils). Trees and other landscape materials shall be <br />planted according to specifications in "CU Structural Soils — A Comprehensive Guide ", as <br />it now reads and as hereafter amended, or using current BMPs as approved by the <br />Director. Suspended pavement systems (Silva Cells or similar) may also be used if <br />approved by the DIreCt01�. <br />{Commented [CL75]: Language is mix of TUC landscaping <br />Il chapter and new text developed by staff. <br />2. For soil preparation in bioretention areas, existing soils must be protected from compaction. <br />Bioretention soil media must be prepared in accordance with standard specifications of the <br />Surface Water Design Manual, adopted in accordance with TMC Chapter 14.30 to <br />promote a proper functioning bioretention system. These specifications shall be adhered <br />to regardless of whether a stormwater permit is required from the City,. <br />Commented [AC76]: Added 2. to acknowledge sons used <br />for bioretention facilities are different from those used for <br />3. For all other plantings, (such as large planting areas where soil volumes are adequate for <br />other planting areas. Reference to TMC 14.30 at request of <br />healthy root growth) soils must be prepared for planting in accordance with BMP T5.13, <br />Public Works staff. <br />"Post Construction Soil Quality and Depth," from the Washington Department of Ecology <br />Stormwater Management Manual for Western Washington (as it now reads and as <br />hereafter amended), regardless of whether a stormwater permit is required by the City. _ <br />-- Commented [CL77]:18.28.240 B.3.b. <br />4. The applicant will be required to schedule an inspection by the City of the planting areas <br />prior to planting to ensure soils are properly prepared. Soil must be amended, tilled and <br />prepped to a depth of at least 12 inches. <br />Commented [CL78]: 4. from 18.28.240 B.3.c. <br />5. Installation of landscape plants must comply with BMPs lincludingl: <br />Commented [CL79]: 5. from 18.28.240 B.3 .d. <br />a. Planting holes that are the same depth as the size of the root ball and two - three times <br />wider than the root ball. <br />b. Root balls of potted and balled and burlapped (B &B) plants must be loosened and <br />pruned as necessary to ensure there are no encircling roots prior to planting. All burlap <br />and all straps or wire baskets must be removed from B &B plants prior to planting. <br />c. The top of the root flare, where the roots and the trunk begin, should be placed at <br />grade. The root ball shall not extend above the soil surface or the flare be covered by <br />soil or mulch. <br />d. If using mulch around trees and shrubs, maintain at least a six -inch mulch -free ring <br />around the base of the tree trunks and woody stems of shrubs. If using mulch around <br />groundcovers until they become established, mulch shall not be placed over the <br />crowns of perennial plants. <br />Page 13 of 19 11/2/2016 6:15 PM <br />W:\ \Long Range Projects \2016 Landscaping Code Update \Draft TMC Chapter 18.52- Advisory Committee Revisions -2 <br />21 <br />