Identifying Boysenberries


When California horticulturist Rudolph Boysen experimented with crossing blackberries, loganberries and raspberries in the 1920s, he created a berry that would eventually take his name. George Darrow of the USDA and Walter Knott, a California fruit grower, discovered and revived the abandoned plants of Mr. Boysen's farm, creating a viable specimen released for sale in 1935. The boysenberry's success sparked Knott's Berry Farm, near Buena Park, California, a popular amusement park. The boysenberry soon became a popular crop in Oregon and eventually reached New Zealand, which is now the world's largest producer of boysenberries.

Step 1

Look for vigorous, woody cane growth with a profusion of thorns when searching for wild berries. Boysenberries, considered invasive in certain parts of the United States, grow in thick tangles when left to grow wild.

Step 2

Look for foliage that is bluish-green in color, with smooth surfaces and serrated edges.

Step 3

Identify small, white blossoms with an open arrangement of five petals surrounding a burst of stamen and pistils in the center in early spring. Boysenberry plants are self-pollinating, producing perfect flowers with both male and female parts.

Step 4

Watch for fruit development when the blooms begin to fade. Boysenberries are considered aggregate fruits, consisting of numerous drupelets which surround a large central seed. In the early stages, boysenberries are light green in color.

Step 5

Check canes for ripened boysenberries in mid summer, beginning in July in the United States. Ripened berries are large and somewhat cylindrical in shape, growing to 1 inch or more in length. The color of ripe boysenberries ranges from reddish-purple to nearly black.

Tips and Warnings

  • Wear protective clothing and sturdy work gloves when working with boysenberry canes to prevent harm from thorns.


  • Berryfruit New Zealand: History of the Boysenberry
  • Oregon Raspberry and Blackberry Commission: Boysenberry Characteristics
  • University of California Agriculture & Natural Resources: Growing Cane Berries in the Sacramento Region
  • The Encyclopedia of New Zealand: Boysenberry flowers and fruits
  • New World Encyclopedia: Boysenberry

Who Can Help

  • Just Fruits and Exotics: Boysenberry-Trailing Varieties
  • Life 123: Growing Boysenberry Plants
Keywords: boysenberry characteristics, aggregate fruit composition, boysenberry foliage

About this Author

Deborah Waltenburg has been a freelance writer since 2002. In addition to her work for Demand Studios, Waltenburg has written for websites such as Freelance Writerville and Constant Content, and has worked as a ghostwriter for travel/tourism websites and numerous financial/debt reduction blogs.