Dormant Kentucky Bluegrass is Going to Last a Little Longer...

With the long range forecast for September and October being similar to August, relief from the drought conditions in many parts of Ohio appears to be far off. The dry conditions for the last two months have raised concern over the long-term effect on dormant Kentucky bluegrass turf. Dormancy is a mechanism that Kentucky bluegrass uses to avoid conditions where inadequate moisture is available for growth. The most noticeable aspect of dormancy is the brownish-tan color of the leaf blades. Although noticeable, leave blades are a minor concern; what is important is the status of the crown. If the crown is damaged then the plant will not recover. If it is healthy then with the arrival of rain (moisture) that crown will generate new leaves and tillers.

The question arises how long can Kentucky bluegrass remain dormant? I have not been able to find any research that answers that question (if anyone knows let me know!). I would say, as long as the crown is healthy the dormancy phase could last indefinitely. A common recommendation is once dormancy has exceeded 6 to 10 weeks a light application of water be made that moistens the crown but does not break dormancy. The belief is that this will prevent death to the crown. It probably would not hurt to apply a light application of water to the turf if you are concerned.

An important management practice would be to reduce traffic or the concentration of wear to the turf. Continual traffic could damage the crown resulting in death. Even with wear as long as it is not intensive and continual, I would still expect turf recovery with the arrival of rain for the reason that Kentucky bluegrass has a rhizomatous growth habit. Growing points along the rhizome are protected by the soil, and as cooler soil temperatures arrive, I would expect new shoot growth from these rhizomes.

Authors: Karl Danneberger