Rubus ursinus × R. idaeus
Boysenberry, probably created by Rudolph Boysen and certainly popularized by Knott's Berry Farm, is a complex cross between the European raspberry, European blackberry, American dewberry, and loganberry. A distinctly tart, juicy treat, these large, red-black berries mature at up to 2 inch long. The harvest of delicious, aromatic fruit continues to ripen for up to two months. Try eating them fresh with cream, mixing them into a smoothie, or baking them into a spectacular pie - exceptional.
Trellising the trailing, vigorous canes on a 2-wire system works well; the first year primocates down low, and the 2nd year floricanes up higher where they will be easy to harvest from. USDA Zones 6-10.