Savannah resident Mary Hill, 71, dug into a garden bed across from Rebecca Elias, a 27-year-old New Yorker who was shoveling out a hole for a tomato plant. Both have more in common than their apparent green thumbs. Elias has committed to a year in Savannah as an AmeriCorps VISTA participant, while Hill serves as a senior companion for Senior Citizens Inc. Each enjoys serving others. “Personally, it’s my duty to help citizens get the resources they need,” Elias said. On Tuesday, some of those resources were being planted by Elias and Hill, along with about two dozen other volunteers, in the form of future produce for seniors, veterans and low-income residents.