During National Forestry Week in 1928, a committee of tree lovers recommended to Portland's city council "that since the City of Portland is now, and for many years has been, one of the largest centers of the lumbering industry of the Northwest, and in recognition of National Forestry Week and of Portland's interest in forestry, it is fitting that a municipal arboretum be established to preserve the various species of conifers for the educational and recreational benefit of future generations."

Hoyt Arboretum was named in honor of Ralph Warren Hoyt, Multnomah County Treasurer and County Commissioner. At one time he was also president of the Rose Festival Association.

The site which is now Hoyt Arboretum was once the Multnomah County Poor Farm. The Farm had been abandoned by the County and been turned over to the City of Portland. The city used a portion of this area for the West Hills Golf Course, but the course was later erased in order to make room for the new zoo. The first trees were planted in Hoyt Arboretum in 1931. The original area had been a dense stand of Douglas Fir, which was gradually reduced in order to make room for different varieties of planted specimens.

Hoyt Arboretum now has one of the largest collections of distinct species of gymnosperms (conifers) of any arboretum in the United States. This collection includes the Dawn Redwood. After becoming extinct eons ago, the Dawn Redwood was reintroduced into the United States from China. The tree bore cones when it was only four years old making these cones the first Dawn Redwood cones produced in the Western Hemisphere in 50 million years.

It can definitely be said that the 1928 committee that lobbied for Hoyt Arboretum was far-sighted in its thinking, for this area has, indeed, become precious to the many generations that have grown up with it.