Iowa State University Extension and Outreach offers lawn care guidance amid Central Iowa watering restrictions

Iowa State University Extension and Outreach is sharing guidance with Central Iowa community members on how to maintain their lawns as the Central Iowa Water Works enforces summer irrigation restrictions.

Adam Thoms, associate professor in the Department of Horticulture and extension turfgrass specialist at Iowa State, and Aaron Steil, consumer horticulture extension specialist at Iowa State, provide the following direction for homeowners.

Cool-season grasses common in Iowa lawns, including Kentucky bluegrass, ryegrass and fescue, naturally turn brown and in summer enter dormancy when rainfall or irrigation is scarce. Although the foliage dies back, crowns and roots remain alive. Most healthy lawns can survive dormancy for four to six weeks without water and recover when moisture returns. 

Homeowners should avoid cycling between dormancy and greening with intermittent irrigation, as this weakens turf. Allow lawns to enter dormancy and remain dormant during extended dry periods.

While dormancy is a natural survival mechanism for cool-season turfgrasses, it has limits. Lawns that remain brown beyond six weeks risk permanent decline. If that occurs, new turf can be seeded in early September when temperatures typically cool and watering restrictions may ease.

Thoms and Steil recommend homeowners also take the following steps:

• Raise mowing height to 3.5–4 inches. Taller grass shades the crown, cools the root zone and promotes deeper, more drought-tolerant root growth. Do not mow dormant turf, as this can cause damage.
• Hold off on fertilizing dormant lawns. Nutrients will not be taken up by the plant and applications should wait until conditions improve in early fall.

While lawn irrigation is currently restricted, newly planted trees, shrubs and other garden plants can be irrigated responsibly as needed. 

Additional information is available on the Iowa State University Extension and Outreach Yard and Garden website, including:

• Watering the Garden and Lawn During Periods of Drought or Water Restrictions
• Summer Lawn Care
• Home Lawn Watering Tips and Tricks
• Watering Home Lawns

PHOTO: Garden sprinkler watering grass at home backyard (Photo: iStock – ronstik)