The Tillinghast Seed Company is believed to be the first seed company in Washington state, if not the Pacific Northwest.

Alvinza Gardner Tillinghast (b. 1845 in Pennsylvania) worked as early as 1873 in Padilla Flats, Skagit County, Washington with two cousins (Rienze^[7] E. Whitney and E. A. Sisson) experimenting with cabbage seed.  In 1877 the partnership was dissolved and Mr. Tillinghast left the area.

For some period of time, he went back to Pennsylvania.  He was recorded in the 1880 Census as living with his wife and parents (Stephen Tillinghast and Tryphena Capwell Tillinghast) in North Abington, Lackawanna County, Pennsylvania.^[7]

He returned to the Padilla Flats, Washington area sometime prior to 1882, was listed as the postmaster in 1882, and by 1885, founded the company.  Seed stock was initially purchased from suppliers in the East and packaging and sales done from his house.  He produced his first seed catalog in 1886 and called the company the Puget Sound Seed Garden.

After relocating from Padilla to La Conner, Washington in 1890, Tillinghast contracted with local farmers to produce cabbage seed.  They set up shop at the entrance to the little town and had fields that spread east toward Pleasant Ridge. Their business grew and their seeds were sold all over the country.

In the 1920s, the company changed its name to the Tillinghast Seed Company and remained under family ownership until 1980 when Ruth Tillinghast Dalan sold the company to Arberta Lammers.

Lammers still (as of 2007) runs a flower and gift shop called Tillinghast in La Conner.  The last seed catalog ended with the 1993 issue and she sold the seed company name in 2003 to a Seattle entrepreneur who also owned the now-defunct Barkley Seed Company name.

The old seedhouse building is now home to a restaurant, appropriately named "Seeds."  The old seed bins and counter reportedly are owned by the Christianson’s Nursery east of La Conner, and most of the old company documents as well as their printing press, reside at the Skagit County Historical Museum.