Johnston officials have decided to remove up to 60 ash trees before an insect pest arrives to kill them.
The officials hope that planting a variety of other species will create a healthier canopy before emerald ash borers reach the Des Moines suburb.
Only trees showing signs of distress will be removed.
Emma Hanigan is an urban forester for the state, and she told The Des Moines Register that Johnston is among the first communities in Iowa to choose to kill large numbers of trees before the beetles arrive.
City officials said they will remove more vulnerable trees, but leave healthy trees standing.
The state says the ash borer has been detected in three Iowa locations so far.
The beetles are native to Asia and were first detected in Michigan in 2002. Since then the insects have killed more than 50 million ash trees.