Tacoma was already serious about dahlias more than a century ago. An American Dahlia Society publication from 1935 noted that Tacoma had one of the country's earliest dahlia societies and that Tacoma was holding significant dahlia shows as early as 1911.
By 1932, the Washington Dahlia Society was holding its annual show inside Point Defiance Park Pavilion. So the connection between Point Defiance and Tacoma's dahlia culture predates today's trial garden by decades.
Then comes the part I think makes your episode.
In 1957, the American Dahlia Society reported that a new Pacific Northwest Trial Garden had been started in Tacoma, specifically with the intention of becoming an official ADS trial garden. That first year, the flowers were already being scored.
Two years later, a 1959 ADS report described 37 varieties under trial at Point Defiance and gave this wonderful geographic detail: the garden sat in a beautiful location overlooking Puget Sound, next to the park's bus depot.
That last detail connects beautifully with your larger Point Defiance story because the transportation landscape was changing around the flowers: the Pagoda had served the streetcars, then buses, while nearby another Tacoma institution was quietly taking root.
What actually happens in that garden
A grower creates a promising new dahlia and sends a tuber or plant to Tacoma. It grows in the same public garden visitors stroll through. Judges examine characteristics such as the bloom, form and overall quality. Parks Tacoma says flowers scoring 85–100 points are included in the annual classification book; the garden reaches its spectacular peak in August, when some plants exceed six feet.
And it's still active. The American Dahlia Society's 2026 information lists the Pacific Northwest–Tacoma Trial Garden at Point Defiance and accepts a limited number of trial entries each season.
So people walking through those beds aren't necessarily looking at yesterday's gardening history.
They may be looking at tomorrow's dahlias.