The last couple of weeks have been especially hard on lawns, athletic fields, and golf courses in parts of Iowa that have experienced high temperatures, drying winds, and a lack of moisture. Ideally turfgrass would receive around 1 to 1.25 inches of rain per week to stay actively growing. That has not been the case in many parts of Iowa. Kentucky bluegrass will go dormant to avoid the drought and will go off color. If the dry conditions persist, some turfgrass cover loss will be expected. Our research area is no different, we have several athletic field research plots which have not received adequate rainfall. The area's which were planted to tall fescue are still green and looking good. Another plot that looks good in these hot dry conditions is the HGT bluegrass plots. The pictures below are a good illustration of differences between turfgrasses on the same site and soil. Hopefully rainfall and cooler temperatures will bring relief for turfgrass in Iowa.
Picture 1. Green tall fescue clumps growing in heat stressed and dormant Kentucky bluegrass.
Picture 2. Overhead shot of dormant Kentucky bluegrass (on the right) next to green and actively growing 'Revolution' tall fescue at the Iowa State Horticulture Research Station.
Photo 3. Heat tolerant bluegrass maintaining a green appearance without irrigation at the Iowa State Horticulture Research Station in Ames.
Photo 4. Healthy and unstressed turfgrass growing in a ring around a broken irrigation head.