Do not fertilize Kentucky bluegrass and other cool-season grasses during the summer months (June, July, and August). The best times to fertilize cool-season grasses in Iowa are spring, mid-September, and late October/early November. When fertilizing the lawn, do not apply more than 1 pound of actual nitrogen per 1,000 square feet in one application.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on . The information contained within may not be the most current and accurate depending on when it is accessed.