Thiessen is an early saskatoon with large, juicy fruit about ⅔ inch across. The berries ripen over an extended period, giving repeated fresh pickings. It suckers less than Northline.

Its early flowering can expose the blossoms to spring frost, an important distinction from later flowering selections.

The original bush was found west of Hepburn, Saskatchewan, and the cultivar was introduced in 1976. Manitoba Agriculture advises against Thiessen in northern Manitoba because of its early flowering and exposure to spring frost.