Two gardens in Livermore and one in San Ramon have been added to the 17th annual Bringing Back the Natives Garden Tour, which is virtual for 2021, and registration is now open.

The tour will take viewers to 25 homes in Alameda and Contra Costa counties with gardens designed with plants native to California that thrive without amendments, fertilizers or pesticides, and offer incomparable habitat value to wildlife.

This year the tour has a new companion event, the Green Home Tour, for a total of four days of garden tours (April 25; May 2, 16, 23) and two days of green home tours (June 6, 12). The tours are free but registration is required at www.bringingbackthenatives.net to receive links to join the live events. The website has the full schedule of events as well as garden descriptions and plant lists.

Douglas Tallamy, author of "Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens" and "Nature's Best Hope," will be the keynote speaker, at 10 a.m. April 25.