Rising temperatures and sunshine pull perennials and a cavalcade of festivals from the winter soil and doldrums. FloraFest: Find gardening inspiration with more than 35 arts and gardening vendors, food trucks, crafts for kids, a beer and Bellini garden, and more, 11 a.m.-3 p.m. Saturday, Cottonwood Center for the Arts, 427 E. Colorado Ave., free; 719-520-1899, cottonwoodcenterforthearts.com.   Denver UkeFest: Ukuleles are smaller than guitars, with four strings instead of six strings, and produce a brighter and cheerier sound. They’re also easier to play. Celebrate them with a day of concerts and workshops. Featured performers include Brittni Paiva, Cynthia Lin and Steven Espaniola, 10 a.m.-10:30 p.m. Saturday, Swallow Hill Music, Daniels Hall, 71 E.…