This post is based on Dr. Tony Koski, Colorado State University Cooperative Extension, recommendations on annual lawn irrigation requirements for the Colorado Front Range area. Please note his recommendations assumptions first.
Supplemental irrigation requirements for the following lawn grass species assume:
- “Normal” precipitation (10-11 inches, April-October) and summer temperatures
- Good irrigation coverage (80% efficient irrigation system coverage)
- Extended drought and/or higher temperatures increase water needs for ALL grasses
§ Kentucky Bluegrass will need 24-26 inches of supplemental irrigation per growing season to produce a lawn of good to excellent quality.
§ Lower (but acceptable) quality Kentucky Bluegrass lawns can be grown with as little as 15-20 inches of irrigation (with normal precipitation and good irrigation coverage)
§ Tall fescue may need 10% less irrigation than Kentucky Bluegrass (20-22 inches) IF it can grow deep roots and substantial subsoil moisture exists
§ Tall fescue may require MORE irrigation than Kentucky Bluegrass if planted on poor/shallow soil, when subsoil moisture is deficient, or where deep rooting does not occur
§ Fine fescue lawns will require 18-20 inches (where it can form deep roots)
§ Buffalograss and blue grama lawns will require 8-10 inches (1-2 inches of irrigation per growing month) for a GOOD quality lawn that will tolerate moderate traffic/use
§ Bermudagrass irrigation requirement is similar to that of buffalograss, or slightly less
§ Kentucky bluegrass, fine fescue, buffalograss and bermudagrass can become dormant and survive prolonged periods (1-2 months) without precipitation and irrigation; tall fescue lawns often die or become thin when deprived of water for similar time periods
Dr. Tony Koski, Colorado State University Cooperative Extension