The Boysenberry is a large bramble berry that grows on trailing vines, rather than upright bushes. Reaching up to 2.5 centimeters in length, they are one of the largest berries in the Rubus genus. They are composed of small druplets each containing a single seed, tightly clustered around a solid core. When fully ripe, they develop a deep maroon color, though it is not uncommon for the berries to still have subtle hints of red. Its flavor is rich and complex, slightly sweeter than a blackberry with just a hint of acid. They have an extremely juicy consistency and fragile texture.
The Boysenberry is a hybrid aggregate fruit that was cultivated by cross pollinating the flowers of three other berries: raspberry, loganberry and the blackberry. Botanically named Rubus ursinus idaeus, it is categorized as a dewberry, which is a trailing thorny plant that it commonly found in North America. Though they look almost identical to the standard blackberry, Boysenberries are valued by some to be a far more special treat. Their extremely thin skin and high moisture content mean that an extended shelf life is almost non-existent. When picked at the perfect ripeness, these highly perishable berries are highly sought after and a coveted item among chefs and culinarians.
Boysenberries are a good source of vitamins A and C, iron, calcium, potassium, phosphorous, magnesium and dietary fiber
Boysenberries can be used similarly to blackberries in most applications, but are slightly sweeter and more fragile. They are commonly used in the typical jam, jelly, or baked good, but are also wonderful in savory appetizers and main entrees. They cook down beautifully into a sauce spiked with wine and black pepper paired with fresh goat cheese and rosemary flatbread. Reduce Boysenberry juice with juniper berries, mustard seed and beef stock for a sweet and savory sauce to pair with roasted beef tenderloin. Other complimentary pairings include coconuts, apricots, peaches, honey, rose, citrus, strawberries, raisins, hazelnut, cardamon, cinnamon, mascarpone, fresh young cheeses, poultry, wild game, pork, chocolate, fino sherry and rum.
Boysenberries have been unofficially deemed a “superfood”. They are a rich source of anthocyanins, natural antioxidants which help to maintain healthy brain cells as well as protect against oxidative damage that leads to brain aging as well as Alzheimer’s disease
The Boysenberry was developed during the Great Depression by Rudolf Boysen, a Swedish immigrant and horticulturist who lived in the Napa Valley region of California. The Boysenberry would later find commercial success under the guidance of farmer and berry “expert” Walter Knott of Knott’s Berry Farm. In fact, it was the Boysenberry’s immense popularity that put Knott’s Berry Farm on the map and made it into the famous farm that we know today. Boysenberries grow on trailing vines throughout the Western Coast of the United States. They have been naturalized in Northern New Zealand, where the fruit is grown for commercial export more than anywhere else.
To get the best growth and flavor, make sure your berries get lots of sun throughout the day. It’s okay if they are in shade for part of the day, as long as they get a lot of sun.
If you aren’t sure where to plant, watch your yard throughout the day to see where the best sunlight is.
Boysenberries won’t grow in soil that holds too much water. Pick a spot in your yard that drains well when you get a lot of rain. Don’t plant anywhere that collects water. Soil that stays soaking wet will cause the plants’ roots to rot.
- Before planting for the first time, always till the soil really well. Use a power-tiller or a hand tool to turn the soil over to about one foot (.3 m) deep.
- Boysenberries grow well in sandy, loamy, or clay-rich soil. They need moist soil, but they are also resistant to drought.
- Boysenberries grow best with something to cling to. Set a pole in the ground at each end of a row of boysenberry plants. Make sure the poles stand three feet (.9 m) above the ground. String two pieces of wire, or a long piece of wire mesh, between the poles. Tie plants to trellis
- Boysenberries go into dormancy during the winter season, so right before they start new growth is the best time to transplant.
- Boysenberries are pretty resilient in the face of cold weather, so they can handle if it stays cold for a little while after you plant them.
- Plants grow into full size throughout the summer.
- Planting depth varies depending on the starting size of plants, but use this as a guide. Plant them about as deep as the container they start in. It’s better to start with a larger hole than you need because you can fill it in as needed.
- Add at least a heaping handful of compost or animal manure or a dry granular fertilizer to the bottom of the hole. This helps give the plant a nutrient boost as it takes root in the soil.
Once the growing area is all ready, place the plant into the hole. Shovel dirt around the roots and pack it down. Place a small layer of compost or manure around the base of the plant once it’s buried in the ground and WATER.
Boysenberries keep growing as much as you let them. It’s important to give them a minimum of three feet (.9 m) to spread before they touch another plant. If you have the room, planing them five feet (1.5 m) apart leaves them plenty of room.Pay attention to the heat in your area. If it is extremely hot, you’ll need to water more often. A soil moisture meter helps you avoid wondering if the soil is wet enough.
Boysenberries are considered brambles, so they spread and expand. To keep the plants upright, tie them to the wires once they grow tall enough. The plants cling to the wire and expand outward along it.
- Use twine or thin string to tie the plants up. Tie them first at the one and a half foot (.45 m) high wire, then at the three foot (.9 m) high wire.
- If you used wire mesh instead of wire, tie the plants at the same heights listed. If you planted along a fence or wall, adapt this tying method to help them cling to the surface.
- Most boysenberry plants need to grow for a full year before they actually produce fruit. Care for the plants throughout the year so you’ll have a full harvest of fruit to pick a year after you plant.
- When your plants produce fruit, go out early in the morning to pick the berries off the plant. The berries are firmest in the morning, which is the best way to harvest them. Eat them, freeze them, or cook with them quickly because they don’t stay fresh for long.
- Boysenberry plants will grow out of control if you let them, so always prune them carefully. Once a cane produces fruit, it won’t produce again during that growing season. Prune the old canes down to the ground in fall or winter.
- Cut the canes that produced fruit down to the ground. Also cut any withered or diseased-looking canes. Compost non-diseased canes for next season
- If your boysenberries are afflicted by serious mold or fungus infections, use an anti-fungal spray. Most types of fungal infections can be treated with copper-based fungicides.