I live in Mercer Co, WV (southern tip of WV) and I would like to know the best time to plant annuals, petunias, etc. I've heard somewhere between May 15 and 20. Plants are expensive and I don't want to take any chances. I don't mind covering them up at night if weather gets bad. I'm also planting a Mandevilla and wanted to know if these are perennials or an annual.
Certified GKH Gardening Expert
Since your zone is 6a-6b, planting annuals should be safe after May 15. Mandevilla is a tender annual. This article should help with growing the plant: https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm