This week

Stars Over Elachee at Chicopee Lake, Gainesville. Learn about astronomy and how to use a telescope to view the night sky. For adults and children 8 and older. Bring a flashlight and pencil. Reservations required. 7:30-9 p.m. Saturday and Sunday and 7:45-9:45 p.m. April 18, Elachee Nature Science Center, 2125 Elachee Drive, Gainesville. $10 adults, $5 children age 2-12, free for Elachee members. 770-535-1976 or http://www.elachee.org/.

Special Trillium Trek Training Clinics. Learn about orienteering, nature facts and first aid. Learn more about the trek. 10 a.m. to 1 p.m. Saturday, March 27, April 17 and 24, Elachee Nature Science Center, 2125 Elachee Drive, Gainesville. Call to register. 770-535-1976 or click here.

Bike ride, Gainesville. Chicken City Cyclists. Hilly, more than 48 miles. 10 a.m. Saturday, Dewberry Church, intersection of Clarks Bridge Road and Glade Farm Road, Gainesville. unnoldl@charter.net. 

Open Garden Forum, Gainesville. Annuals and perennials. 1 p.m. Wednesday, Gardens on Green, 711 Green St., Gainesville.

Upcoming

Bike ride, Gainesville. Chicken City Cyclists. More than 30 miles; moderate. 10 a.m. March 27, Dewberry Church, intersection of Clarks Bridge Road and Glade Farm Road, Gainesville. unnoldl@charter.net.

Spring Garden Expo, Gainesville. Hall County Master Gardeners. More than 60 vendors selling plants, garden art and products; activities for kids and "Ask a Master Gardener" information booth. 8 a.m. to 6 p.m. April 9 and 8 a.m. to 4:30 p.m. April 10, Chicopee Woods Agricultural Center, 1855 Calvary Church Road, Gainesville. Free admission and parking. 770-535-8293.

Ongoing

Triathlon Club, Gainesville. No experience necessary. Meets 7 p.m. second Tuesdays, Fit 2 Tri Store, 1292 Thompson Bridge Road, Gainesville. 770-712-9129 or fit2tri@gmail.com.

ISI Cycling ride, Gainesville. 35-45 mile ride. No ride in rain or temperature less than 36 degrees. 1 p.m. Sundays, Kroger Shopping Center, 3630 Thompson Bridge Road, Gainesville. 678-231-0417.