Love Gardens? The Pima County Extension Master Gardener Program offers free guided tours of its 14 gardens that showcase what you can grow in the desert. The 90-minute tour begins at the Pima County Extension Office at 4210 N. Campbell Ave. every Wednesday and Saturday morning beginning at 9 am.( September-December, except October 8, Thanksgiving and Christmas weekends, and February-May Masks preferred; Toed Shoes, hat, sunscreen and water bottle are recommended.