April is Arbor Month with Portland Parks and Recreation: “Celebrate our beautiful urban forest during Arbor Month, April 2013! Discover Portland’s 300 Heritage Trees and join us for our many tree walks, classes, workshops and more. Learn how Portland’s trees work 24/7: filtering our water, cleaning our air, cooling the city, providing wildlife habitat, enhancing livability, and increasing property resale value. Join in the Arbor Day Festival on April 20th, Portland Farmers Market at Portland State University!”
A schedule showing all events is here.