GARDENING Events This Week FALL TREE PLANTING. Civano Nursery. 5301 S. Houghton Rd. The best time to plant most desert trees is the Fall. Learn how to select and plant them on Saturday, September 14 at 9 a.m. Free but call to reserve a space at 546-9200. HYDROPONIC GARDENERS. UA Agri-Farm Greenhouse. 2031 E. Roger Road. This group meets at noon the second Saturday of every month. Call Bob at 327-8822 or Jo at 751-1005 for information. NATURE CONTROLS FOR INSECT PESTS. Pima County Cooperative Extension. 4210 N. Campbell Ave. Free gardening demonstration includes diagnosis and treatment tips on Wednesday, September 18 at 9 a.m. and repeated at 1 p.m. at Wilmot Library. Call 626-5161 for details. ORGANIC GARDENERS MEETING. St. Mark's Presbyterian Church. 3809 E. Third St. Gail Barnhill talks about water gardens on Tuesday, September 17 at 7:30 p.m. Stop by at 7 p.m. for informal discussion with garden experts and a mini market. Call 670-9158 for details.