Up ahead

Introduction to Trilliums

Jeanne Frett, research horticulturalist, Mount Cuba Center, talks about this native wildflower from 2 to 3 p.m. Jan. 4 at Bowman's Hill Wildflower Preserve, 1635 River Rd. (Route 32), New Hope; 215-862-2924;

» READ MORE: www.bhwp.org

. Free; pre-registration suggested.

Preparing Your Soil for Planting

Program with Montgomery County Master Gardeners at 7 p.m. Jan. 12 at the Penn State Cooperative Extension, 1015 Bridge Rd., Collegeville. Fee: $15; pre-registration and payment at least seven days in advance. Information: 610-489-4315,

, click on "horticulture, "programming," "garden study series."

Deciduous Tree Identification

Indoor-outdoor class, sponsored by Penn State University Extension from 9 a.m. to 3:30 p.m. Jan. 19 and 20 at Delaware County Extension (indoor), 20 Paper Mill Rd., Springfield, and Swarthmore College, Scott Arboretum (outdoor), Route 320 and College Avenue, Swarthmore. Fee: $150, includes coffee, refreshments; lunch is on your own. Registration deadline is Jan. 11: 610-696-3500. Dress appropriately for weather.

- Jerene Schroeder

Submit items for "Garden Calendar" three weeks in advance to jschroeder@phillynews.com or at The Inquirer, Box 8263, Philadelphia 19101. Include a contact person, address and phone number.