Poa annua control and late aerification on golf courses

Last updated 9/30/03

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9/30/03

Poa annua control and late aerification on golf courses

Given golf schedules and complications from fall rains this year, many courses are aerifying much later than desired. Aerfying during the cool temperatures of late September and October slows recovery of turf and may even allow for open aerification holes throughout the winter. Poa annua germination peaks in September and October, but will continue to germinate throughout a warm winter and well into spring. Open turf from late aerification will encourage Poa annua germination. Additionally, bringing soil cores to the surface will also bring viable Poa seeds to the surface further encouraging germination. The best method to help limit Poa encroachment at this time of the year is with preemergence herbicides. A number of products are labeled for Poa annua control and applications around Labor Day are most effective. However, if no preemergence herbicide was applied yet and aerification is still scheduled for this year, it’s not too late to apply. A benefit of applying preemergence now is that it will continue to limit Poa germination throughout the winter and spring and will prevent summer annuals like crabgrass from germinating early next summer. We have found that the high rate of preemergence herbicide is necessary for the longest control of crabgrass and a second application may be needed late next spring for season-long control of crabgrass.

Zac Reicher, Associate Professor/Turfgrass Extension Specialist