What is a boysenberry?
Boysenberries are large composite drupelet fruit with large seeds and a dark red colour (from red to black), averaging eight grams, characterized by their soft texture, thin skins, and sweet-tart flavour. They grow on low, trailing plants which require support.
The Boysenberry (Rubus ursinus var loganobaccus cv Boysenberry) is a Rubus hybrid berry and believed to have arisen from a cross between loganberries, raspberries and blackberries in the 1920s in California by Rudolph Boysen, although they were first produced in any quantity and sold to the public by Walter Knott, which made Knott’s Berry Farm famous.
In the 1980s in New Zealand, Hortresearch (now Plant and Food Research Ltd) combined cultivars and germplasm from California with Scottish berry sources to create new thornless varieties.
New Zealand is the world’s largest producer and exporter of Boysenberries.
They are mainly grown in the Nelson-Marlborough region, which has the highest average number of sunlight hours in the entire country. This plus the high UV levels of this part of the southern hemisphere is likely to result in high phenolic levels of the fruit, particularly the anthocyanins which give the fruit its colour.
New Zealand Boysenberry has greater amount of dietary fibre, total phenolic concentrations, total anthocyanin concentration and greater anti-oxidant activity (ORAC) than Chilean Boysenberry (Lister et al., 2008)(figure 1). ORAC stands for oxygen radical absorbing capacity, a measure of total antioxidant activity.
Figure 1. Comparing Boysenberries from New Zealand and Chile.
Boysenberry has greater total phenolics concentration, total anthocyanin concentration and ORAC and FRAP antioxidant activities than blackberry and blueberry (figure 2). FRAP stands for ferric reducing antioxidant power, a different measure of antioxidant activity.
Figure 2. Comparing Boysenberry vs blackberry and blueberry
New Zealand Boysenberry contains high proportion of key nutrients relative to dietary energy. This can be expressed as Nutrient Adequacy score (figure 3). Nutrient Adequacy is a nutrient density rating: how much key nutrients in relation to the dietary energy they provide (Darmon et al., 2005).
Figure 3. New Zealand Boysenberry has a very high nutrient adequacy score compared to other common fruits
Boysenberry vs blackberry vs raspberry
A boysenberry is a hybrid with raspberry, blackberry, dewberry and loganberry in its parentage. It looks like an oversized, darker blackberry, and Oregon State University Extension classes it as a blackberry because the white core stays inside the fruit when it is picked. A raspberry leaves that core on the plant and comes off hollow.
| Feature | Boysenberry | Blackberry | Raspberry |
|---|---|---|---|
| Parentage | Hybrid of raspberry, blackberry, dewberry and loganberry | Blackberry species (Rubus) | Red raspberry (Rubus idaeus) |
| Core when picked | Stays in the fruit | Stays in the fruit | Hollow, core stays on the plant |
| Colour | Deep maroon to near black | Black | Usually red |
| Size | Large, about 8 g | Typically smaller | Typically smaller |
| Flavour | Sweet-tart | Sweet to tart | Tart |
| Handling | Soft, thin skin, spoils within days of picking | Firmer | Very delicate |
If you remember one thing, make it this: the boysenberry is the big, soft, deeply coloured one, and it travels badly, which is why most of the world meets it frozen or as jam.
Is a boysenberry just a blackberry?
Not quite. It is grouped with the blackberries because of the way it comes off the plant, but it is a cross with raspberry and loganberry in its family tree. It is larger, softer and more maroon than a typical blackberry, and it bruises and leaks juice far more easily.
Where the boysenberry came from
The boysenberry is named after Rudolph Boysen, a grower in Anaheim, California, who worked with the plant in the 1920s before giving up his experiments and selling his farm. In the late 1920s George Darrow of the US Department of Agriculture went looking for the large reddish-purple berry he had heard about, helped by local berry farmer Walter Knott. They found a few frail vines still alive on Boysen’s old farm and moved them to Knott’s farm in Buena Park.
So did Knott’s Berry Farm invent the boysenberry? No, but it made the berry famous. Walter Knott was the first to grow it commercially, started selling it at his farm stand in 1932 and named it after its originator. His family’s pie and preserves business grew into Knott’s Berry Farm.
Where New Zealand boysenberries grow, and when they are picked
New Zealand is the world’s largest producer and exporter of boysenberries, and growing is centred on the Nelson and Tasman area at the top of the South Island. One Nelson grower picks three cultivars, Tasman, Mapua and Riwaka, which ripen at different times and stretch the harvest.
The window is short. That grower describes switching the harvesters on around 15 December, starting at 4am and finishing by midday, with the whole harvest taking about a month (HortNZ, December 2021). So the season runs roughly from mid-December into January. Weather decides the rest: the same grower had three poor crops in a row, mainly because of the weather.
The fruit is so soft that most of the crop goes to freezing, juice concentrate or purée for local and export markets. Fresh boysenberries are a December and January treat in New Zealand and rare elsewhere. New Zealand breeding in the 1980s also produced thornless varieties.
For how New Zealand’s sunshine and UV shape the fruit, plus what the research says about boysenberry benefits, see our companion page.
Why boysenberries are hard to find
Ripe boysenberries leak juice easily and can start to decay within a few days of picking, so they do not survive long supply chains. California’s boysenberry plantings peaked in the 1950s, then shrank from the 1960s as growers moved to newer berries that were easier to grow, less prone to fungal disease and tougher to ship.
Today most of the crop is frozen or turned into jam, pie filling, juice, syrup and ice cream. Fresh fruit mostly reaches local farm stands and markets during the short summer season. The rest of the year, frozen boysenberries are the easiest way to buy them.
Can you grow boysenberries?
Yes, with full sun and fertile, well-drained, slightly acidic soil (about pH 5.6 to 6.5). The plants are low, trailing canes, so they need a trellis or wires. Commercial rows sit 2.4 to 3 m apart with plants 60 to 75 cm apart along the row, and bees do the pollinating. Thornless varieties make picking a lot less painful.
Are boysenberries good for you?
As a fruit, yes. Per 100 g, frozen unsweetened boysenberries provide about 5.3 g of fibre and 63 mcg of folate for 50 kcal (USDA), plus anthocyanins, the pigments behind the dark colour. In a New Zealand laboratory comparison, boysenberries measured higher in total phenolics, anthocyanins and antioxidant activity than blackberries and blueberries (Lister et al., 2008).
Claims beyond basic nutrition need more care. Most boysenberry research is lab and animal work, and the human studies so far tested BerriQi®, a standardised boysenberry and apple ingredient, not fresh fruit. Boysenberry benefits: what the research shows sets out each study and what it does and does not prove. Food and supplement brands can source BerriQi through Anagenix’s distributor network.
What boysenberries taste like and how people use them
Expect a sweet-tart flavour, a soft, juicy texture and large seeds you will notice. Eat fresh ones within a couple of days, because they can begin to decay within days of harvest.
Most of the crop becomes jam, pie filling, juice, syrup and ice cream. At home, frozen berries are the practical choice for baking, smoothies and sauces.
BerriQi® takes a different path. It is a patented boysenberry and apple ingredient whose powder is described as sweet with tangy berry overtones, made for supplement and functional food brands rather than the fruit bowl. The ingredient page explains it: New Zealand boysenberries for respiratory health.
Boysenberry FAQ
What is a boysenberry?
A large, soft, deep maroon hybrid berry with raspberry, blackberry, dewberry and loganberry in its parentage. It was first grown commercially in California in the early 1930s, and New Zealand is now the largest producer.
Is a boysenberry just a blackberry?
It is classed with the blackberries because its core comes away inside the fruit, but it is a hybrid that also has raspberry and loganberry in its parentage. It is bigger and much softer than most blackberries.
What does boysenberry taste like?
Sweet-tart, juicy and soft, with large seeds you will notice. Most people know the flavour from jam, pie and ice cream rather than from fresh fruit.
Why is boysenberry so hard to find?
The ripe fruit is very soft and can start to decay within days, so it does not ship well. Most of the crop is frozen or processed, and fresh berries mostly sell at farm stands during the short summer season.
When is boysenberry season in New Zealand?
Roughly mid-December into January, with the exact timing set by cultivar and weather.
