Activities in celebration of Earth Day are planned at several of the East Bay Regional Parks in coming days; you can take your pick.

At the Tilden Nature Area in Berkeley, interpretive student aide Julia Burks will lead an Earth Day recycling program from 2 to 3 p.m. Saturday at the Environmental Education Center. Julia will show how to make biodegradable pots out of old newspaper, perhaps including this column, then use them to plant veggies right in the ground. At the same time and place, Julia will show how to make baskets out of natural and recycled materials.

Both programs are free, intended for ages 5 and older. The center is located at the north end of Central Park Drive. However, because of ongoing construction, you have to get there by parking at the end of Lone Oak Road off Central Park Drive, then following the directional signs. For information, call 510-544-2233.

BOTANIC GARDEN: Although it isn't directly related to Earth Day, another big event at Tilden this weekend is the annual plant sale at the Regional Parks Botanic Garden. This is your chance to buy all kinds of native plants to beautify your garden and get expert advice on how to care for them.

The sale lasts from 10 a.m. to 3 p.m. Saturday. However, the garden gates open at 8:30 a.m. Sale veterans get there early to be at the front of the line and assure a good selection. Bart O'Brien, the new garden director, will make the opening announcement.

Volunteers from the California Native Plant Society help with the sale. All proceeds are used to fund Botanic Garden programs. The sale takes place rain or shine. Please bring empty boxes to carry your purchases home. Parking and garden entry are free. For information, call 510-544-3169.

TRAIL WALK: At Crab Cove Visitor Center in Alameda, supervising naturalist Sharol Nelson-Embry will celebrate actual Earth Day with a walk along the San Francisco Bay Trail from 7:30 to 9 a.m. Tuesday in search of shorebirds and ducks. Binoculars will be available for loan. The walk is free, and the visitor center is located at 1252 McKay Ave. off Central Avenue. For information call 510-544-3187. Rain cancels.

There's also an Earth Day-themed coastal cleanup event at Crab Cove and Crown Beach from 8:30 to 10 a.m. April 26 designed for ages 4 and older. The group will clean up ponds and the beach. Students can earn community service hours by participating. Registration is required. To register, call 888-327-2757. Select option 2 and refer to program number 5246.

Coyote Hills: All sorts of Earth Day-themed activities are planned from 9:30 a.m. to noon and 1:30 to 4 p.m. Saturday at Coyote Hills Regional Park in Fremont, hosted by naturalist Dino Labiste.

Kids will be able to create their own litterbug craft, play recycling games, and enjoy environmental puppet shows starting at 11:40 a.m. and 3:40 p.m. Coyote Hills is located at 8000 Patterson Ranch Road off Paseo Padre Parkway north of Highway 84. There's a parking fee of $5 per vehicle; Earth Day activities are free. For information, call 510-544-3220.

Martinez, carquinez: What else? Well, there's an Earth Day sunset stroll from 6 to 8 p.m. Tuesday at Martinez Regional Shoreline in Martinez, led by naturalist Ashley Elliott. It's free; meet Ashley at the front parking lot on North Court Street, across the railroad tracks from downtown Martinez. Ferry Street is the track crossing, and then bear right. For information, call 888-327-2757, ext. 2750.

And naturalist James Wilson will lead a history hike for 5 miles from 2 to 4:30 p.m. Saturday at Carquinez Regional Shoreline near Port Costa. He'll talk about the town's days as a major grain-shipping port. Meet James at Eckley Pier. It's at the park's Bull Valley staging area, which is on Carquinez Scenic Drive between Crockett and Port Costa. For information, call 510-544-2233.

Antioch, Oakley: At Black Diamond Mines Regional Preserve in Antioch, naturalist Ashley will show a collection of eggs laid by animals from near and far. She'll be at the park's uppermost parking lot from 11 a.m. to 2 p.m. Sunday. It's at the end of Somersville Road, 5 miles south of Highway 4 in Antioch.

And the salmon life cycle will be described in a program from 2 to 3 p.m. Sunday at Big Break Regional Shoreline in Oakley. The interpretive staff will talk about some of the obstacles faced by salmon as they swim from oceans to rivers in order to spawn. Big Break is at 69 Big Break Road off Main Street in Oakley. For information, call 888-327-2757, ext. 3050.

Ned MacKay writes a regular column about East Bay Regional Park District sites and activities. Email him at nedmackay@comcast.net.