Read Full Story Spring flowers and new leaves at the Arnold Arboretum of Harvard University signal the return of schoolchildren for outdoor field study experiences. For three decades, the Arboretum has reached out to students from Boston schools to participate in structured explorations of the collections, life science instruction, and engaging interactions with the natural world. This season the Arboretum welcomes hundreds of science students from pre-school through primary grades with new programs, an enhanced partnership for in-class instruction at a neighborhood elementary school, and six additional volunteer guides.Beginning in April, young explorers delve into the landscape through five educational programs designed for hands-on learning. The youngest participants—pre-schoolers from Head Start and kindergarten students—discover plants, animals, and habitats in the Explorations program. Boston’s first-grade students explore living things and their habitats in the Organisms program, and second-grade students compare plants grown in the classroom with the Arboretum’s mature tree specimens in Old Plants. Upper elementary school grades investigate how flowers make seeds in Flowers Change, and compare evergreen conifers and deciduous flowering trees and their cultural uses in Native Trees/Native Peoples.