HomeMy WebLinkAboutCORRESPONDENCE - PURCHASE ORDER - 9182244 (2)Scope of Work:
This scope of work includes revegetation for the total landscaped area of Timberline Recycle Center as
shown below. Work will begin with removal of existing vegetation/weeds from the Timberline Recycle
Center. The site will be sprayed with herbicide twice (during April), and then existing vegetation will be
removed (late April to early May). Native seed will be placed (early to mid-May) at a rate of a minimum
of 18-25 lbs of seed per acre for drill seeding or 35 to 45 pounds PLS per acre broadcast seeding rate.
Irrigation will be analyzed for coverage and additional repairs/modifications will be made. An irrigation
schedule will be prepared (based on information included below) for establishment of the native seed.
Seed germination will be analyzed 14-21 days after seed is placed and irrigation has begun.
Monthly weed control is not included in this scope.
Site Areas:
North facing slope: +61,860 sf (blue)
South facing slope: +58,900 sf (yellow)
Front entry native only: 8,653 sf (orange)
Front entry tree area: 10,420 sf (red)
Solar area: 11,680 sf (pink) unirrigated
Future expansion area: 12,950 sf (green) unirrigated
Total Landscaped area: 164,463 sf (3.77 acres)
DocuSign Envelope ID: DA7F957C-1AFD-42A2-9586-76A2C3E5A37E
Seed Mix:
Bouteloua gracilis blue grama (50%); Buchloe dactyloides buffalograss (30%); Schizachyrium scoparium
little bluestem (20%); possibly Koeleria macrantha, prairie Junegrass
OR contractor recommended 40-35-15-10 mix of Buffalo Grass, Blue Gramma, Blanket Flower, Little
Bluestem mix
Seeds germinate when soil is warm. When looking at 2” soil temps, it appears most likely to hit soil
temperatures of 60-65 degrees starting after mid-May, on average. Soil temperatures:
https://ccc.atmos.colostate.edu/~autowx/fclwx_current.php
On average, seeding rates for upland areas are approximately 18-25 lbs of seed per acre for drill seeding.
Broadcast seeding rates of 35 to 45 pounds PLS per acre are adequate for most dryland broadcasting,
depending on the plant species in the mix.
Irrigation1
Monitoring of irrigation is a critical management activity that should occur if irrigation is to be used on a
site. Either too much water or too little water can be detrimental to the survival of newly planted
seedlings and plantings. Soil type will also influence the amount of irrigation needed since clay soils
require less water to remain moist than do sandy soils. Moist soils in April encourage cool season native
species to grow, whereas warm season grasses start to grow when soil is warmer with adequate
moisture in mid to late May.
In order for native seed to germinate, the top 1 to 2 inches of soil should be moist, but not saturated.
Initial irrigation should maintain moist soil in the seed bed, watering up to twice a day. Use of mulch or
landscape fabric will reduce the frequency of irrigation required to maintain surface moisture. Once the
grasses begin to establish, the roots will penetrate into the soil more deeply and irrigation should be
reduced to three or four times a week, but for a longer duration, to allow for up to 6 inches of moisture
in the soil. Irrigation should then be curtailed to one to two times per week later in the summer until the
fall months when irrigation would cease to allow the plants to harden for the winter months. Table 13-
11 provides a sample irrigation schedule for establishing native areas. Mulching/crimping/
hydromulching seeded areas is also crucial to keep moisture in the soil.
1 https://udfcd.org/wp-content/uploads/uploads/vol2%20criteria%20manual/13_Revegetation.pdf
DocuSign Envelope ID: DA7F957C-1AFD-42A2-9586-76A2C3E5A37E
After seeding:2
Warm season grasses are slower to germinate than cool season grasses, often taking 14-21 days before
the seedlings can be seen.
Herbicide:
General Area Sprayed: Native Areas Timberline Recycling Center
Trade Name: 2,4-D & Roundup
Active Ingredient: 2,4-D (2,4-Dichlorophenoxyacetic acid) & Glyphosate
To Control: Kochia, Bindweed & other unwanted weeds in native areas at Timberline Recycle Center
Record spraying in spraying log. File emailed.
2 The Use of Native Warm Season Grasses for Critical Area Stabilization Christopher F. Miller1 and John A.
Dickerson2
DocuSign Envelope ID: DA7F957C-1AFD-42A2-9586-76A2C3E5A37E