A Spring Nursery Survey is conducted, annually, by Plant California Alliance, PlantRight. UC Master Gardeners and other groups, obtain information about the availability of California invasive plants in the retail market. The survey involves visiting nurseries to count the number, size, and grower of 16 different invasive plants. The list of the plants changes from year to year. The San Mateo/San Francisco Gardeners have been participating for 10 years.