[11] The Humboldt Botanical Garden is particularly interested in maintaining complete native conifer, Iris and Lilium occidental (western lily) collections.

Its Mission Statement is: To cultivate a garden that provides an enjoyable discovery into the botanical world through education, participation and community service.

[3] In March 2023, HBG became the northernmost site for safeguarding the state-listed endangered species Vine Hill manzanita (Arctostaphylos densiflora) which is native to Sebastopol, Sonoma County, California.

[14][15][16] Another critically endangered species is the Wollemi pine (Wollemia nobilis), a native of Australia which has been planted at HBG.

[18] As of 2024, this has included research into Monterey Pines (Pinus radiata), habitats for native pollinators and their flower selection, removal of invasive species, and studying the effects of potential predation on foraging habits of bumblebees.