The soil condition and quality on all graded slopes must provide an optimum growing environment for plant materials in order to promote rapid and healthy plant growth for an extended period.
.010 Soil Tests. Fertility soil samples of all slopes shall be taken and a report prepared by a recognized professional soils laboratory.
.020 Soil Additives and Amendments. Soil conditioners such as nitrohumus, nitrolized redwood, fir or pine shaving, etc., nitrous additives such as nitrogen, phosphorous, potash, soil sulfurs, etc. and other soil elements shall be added in the amounts prescribed by the soils laboratory.
.030 Weed Control. Pre-emergent herbicides shall be employed on all slopes except those which are hydro-seeded and post-emergent contact herbicides shall be employed on all planted slopes to destroy the majority of prevalent annual grasses and broadleaf weeds. Application methods and rates shall be outlined by the responsible landscape architect, and should include prewatering slopes daily to allow maximum weed seed germination prior to post-emergent control.
.040 Nurse Crop. A temporary ground cover may be seeded to provide immediate or temporary slope protection on slopes. The nurse crop must be a noncompeting variety or mix that will allow permanent ground cover and shrubs to prevail. Such temporary ground cover may be hydro-seeded.
.050 Irrigation Application. Maximum irrigation application rates shall be specified for each graded slope. Application periods, as a function of precipitation rates, shall be specified in the soils laboratory report. Periods between such applications shall be specified by the responsible landscape architect. (Ord. 3411 § 2 (part); April 1, 1975.)