Guide to pre-planting from Albright Seed.

Pre-Planting Guide
For disturbed site left unplanted a year or more;
finish grading and clearing complete.

H MINUS 55 DAYS: Kill existing weeds using Glyphosate herbicide such as Roundup®. Apply fertilizer to stimulate dormant weed seed.
H MINUS 45 DAYS: Install irrigation system. Test soil for needed amendments. Remove pre-killed weeds—rake furrows on slopes horizontally if possible. Irrigate to germinate weed seed and continue periodic irrigation until weed growth is about 5 inches. Stop irrigation.
H MINUS 30 DAYS: Kill new weeds using glyphosate contact herbicide. DO NOT remove dead weeds—this could bring ungerminated weed seed to the soil surface Hydraulically amend soil with amendments identified in soil test. Irrigate to germinate second crop of weed seeds—the irrigation will incorporate the amendments into the soil. Check sprinkler coverage by observing weed emergence. Call your irrigation contractor to adjust sprinkler heads as required. Avoid disturbing the soil as much as possible.
H MINUS 25 DAYS: Install trees and large shrubs.
H MINUS 15 DAYS: When second weed growth is approximately 5 inches, kill off with contact herbicide. DO NOT remove dead weeds to avoid bringing more weed seed to the soil surface.
H MINUS 15 DAYS: Install small shrubs and ground cover.
Note: small shrubs and trees and ground cover may be included in the hydroseed mix to eliminate this step and associated expense.
HYDROSEED DAY!: Optional: spray preemergent weed seed inhibitor. USE CAUTION.

See H-DAY PLUS Irrigating the Investment