Boysenberries are a blackberry, raspberry, and loganberry hybrid created by Walter Knott of Knott's Berry Farm and named for his friend Rudolph Boysen who initially began experimenting with creating this new berry hybrid. Knott's Berry Farm has a whole festival dedicated to this fruit. Some key differences between boysenberries and their common cousins blackberries and raspberries are the fruit size, color, and sweetness. Boysenberries produce larger fruit that ripens to a deep purple color that's somewhere between the color of blackberries and raspberries. The berries are slightly sweeter than blackberries but also offer a sharp tartness, too. The fruit is great for making jams, pies, or just as a snack by themselves. This plant is self-fertile.