The Humboldt Botanical Gardens (18 ha / 44.5 acres) are located at the southern edge of Eureka, California, United States. The Gardens are placed near the South Bay portion of Humboldt Bay directly across Tompkins Hill Road from College of the Redwoods. Grading and site preparation for the Gardens began in August 2003. The garden opened in 2006, with more development completed by 2008. The Humboldt Botanical Gardens offices are located in Downtown Eureka.
The Gardens were first organized in 1991. Its Lost Coast Brewery Native Plant Garden has an emphasis on the Humboldt region, but includes plants in the geographic area from the Rogue River to the north shore of San Francisco Bay, and inland to a north-south line running from Vacaville through Williams, Redding, Yreka, Medford, and along the Rogue River to its mouth. The Gardens are particularly interested in maintaining complete native conifer, Iris and Lilium occidentale (western lily) collections.