The city is alerting Boston’s green thumbs that they have until July 11 to register for the 2018 Mayor’s Garden Contest presented by the Boston Parks and Recreation Department with a grand prize provided by JetBlue. Now in its 22nd year, the contest recognizes gardeners who have landscaped, planted flowers, trees, and shrubs, and, in the process, helped beautify Boston’s neighborhoods. Gardeners or those nominating their favorite gardeners may find printable and online nomination forms at boston.gov/mayors-garden-contest. First place winners will receive the coveted “Golden Trowel” award from Mayor Marty Walsh and prize packages from the Parks Department, Mahoney’s Garden Centers, and other sponsors at an awards ceremony in August in the Boston Public Garden presented with support from Polar Beverages. First place winners in this year’s Garden Contest will also be entered into a drawing for a JetBlue Grand Prize consisting of roundtrip flights for two to any nonstop destination from Boston (terms, conditions, and blackout dates apply).