From 10 a.m. to noon Sunday, May 18, James Monroe’s Highland and the Piedmont Master Gardeners will host a plant swap at the historic estate. Swappers can exchange pest-free plants for a variety of other plants for summer gardens. Leftover seeds and non-native, non-invasive plants, including vegetables, also can be swapped. In addition, visitors are welcome to swap pots and garden implements. While supplies last, there will be extra plants available for swappers to take home. A Help Desk staffed by Master Gardeners will provide tips on native alternatives to non-native plants and will show how to identify and remove invasive plants from home landscapes. James Monroe’s Highland is at 2050 James Monroe Parkway in Charlottesville.