Christmas tree recycling for New Castle County (Delaware) residents: trees free of ornaments, tinsel, wire and stands, from 8:30 a.m. to 4:30 p.m. through Jan. 18 at the following Community Yard Waste Demonstration Sites: Brandywine Hundred, north side of Cauffiel Parkway, east of intersection of Cauffiel Parkway and Philadelphia Pike, north of Wilmington; Polly Drummond Hill, Polly Drummond Hill Road, just north of Kirwood Highway, near Newark; DART Mid-County, southwest corner of intersection of Routes 13 and 72, near Bear. Free. Information: 302-739-9902, www.dnrec.delaware.gov.
Seed Starting Learn to successfully start seeds indoors at 9 a.m. Jan. 9 with Philadelphia Master Gardener Loretta DeMarco at the Horticulture Center, West Fairmount Park, Belmont Avenue and Montgomery Drive. Fee: $10; preregistration required: 215-471-2200, Ext. 100. Information: http://philadelphia.extension.psu.edu.
The Story of a Bucks County Green Roof Talk by Barbara Geller and Jane Wilson from 2 to 3 p.m. Jan. 10 at Bowman's Hill Wildflower Preserve, 1635 River Rd. (Rte. 32), New Hope. Free; preregistration required: 215-862-2924. Information: www.bhwp.org.
Developing a Landscape Design Program with Montgomery County Master Gardeners at 7 p.m. Jan. 14 at the Penn State Cooperative Extension, 1015 Bridge Rd., Collegeville. Fee: $20; preregistration and payment at least seven days in advance. Information: 610-489-4315; http://montgomery.extension.psu.edu, click on "horticulture," "coming events," "garden study series."
Glass Bowl Terrarium Workshop with horticulturalist Sharon Kaszan from 10 a.m. to noon Jan. 14 at Meadowbrook Farm, 1633 Washington Lane, Abington Township. Fee: $70 includes all materials; preregistration required: www.pennsylvaniahorticulturalsociety.org/calendar. Information: firstname.lastname@example.org, 215-988-8869.