Volunteers from Southwest Airlines spent this morning installing about 300 new plants in Hemming Park. Several thousand hostas, caladiums and blooming varieties have been installed, said Cathy Catalanotto, owner of Nature’s Way Landscape Management Co., who has the contract to keep the park green. “It’s an ongoing process,” she said. The new plants are in place just in time for Art in the Park and Vagabond Flea, events scheduled 10 a.m.-4 p.m. Saturday.