Four Steps to Perfect Boysenberries

Grandma’s Thornless Boysenberries

We picked our first boysenberries today!

I’ve picked my fair share of blackberries and boysenberries but I’ve never grown them before. As a kid we used to pick blackberries by the gallon in a huge vacant lot near our cabin in Monte Rio, California. The plastic buckets hung from strings around our necks so that we could pick with both hands.

The berry patch was massive with tunnels and rows made from old planks that were smashed down over the vines. It was hot and humid. Our hands were purple, itchy, and sticky by the time we finished. We kept wet washcloths in the car for afterward.

At Phipp’s Country Store and Farm near Pescadero, CA, you can pick olallieberries and strawberries then cap it off with a day at the beach.

Our Thornless Boysenberries berries were given to us by Grandma Rita who lives with Grandpa Ed up in Washington. She occasionally brings us goodies. The lillies she gave us are just beginning to bloom.

A couple years ago she brought a hunk of thornless boysenberries from her wonderful garden. It was in a one-gallon can. We didn’t have a place to put it at the time, so I proceeded to abuse the poor plant. I moved the can around the garden and often forgot to water it. That berry plant died and came back to life many times before we finally planted it.

Eventually, we bought a trellis at Costco and set it up in the garden. I split the vine in two and planted one on each side of the trellis.

We don’t have the room to plant the berries in the “proper” manner, namely a one or two-wire trellis row as outlined below. Given this year’s production, I’m not too worried about it. Our thornless boysenberries are watered regularly and get VF-11 plant food weekly during the growing season.

To properly maintain boysenberries, you need to learn two new words: primocane and floracane. Primocanes are the new stems that grow this year. They do not produce berries in year one. The Floracanes are last year’s growth and produce this year’s flowers and berries.


1. After fruiting in the summer, cut floracanes down to the ground.

2. Tie this year’s primocanes onto trellis and prune to 6-8 ft.

3. Thin semi-upright varieties to 4-8 canes.

4. In early Spring, cut side branches back to 12 inches.

More blackberry tips: Pruning and Training Thornless Blackberries

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11 Responses to “Four Steps to Perfect Boysenberries”

  1. Deana Wendlng Says:

    Hope someone can help me.
    We recently moved to Perris California -been there for 3 months now.
    Transplanted my boynesberries, over 100 of them and now that the weather has turned terribly hot, over 100-110 degrees, it looks like about half of my boynesberries are dying. Now my husband says I am over watering them–how much water in hot weather do you put on them.??
    I try to water in the mornings-dug a small berm around each one, still some are not doing so well-
    can you help me?

  2. Chris Says:

    From my research, it looks like the biggest problem with transplanted boysenberries is planting TOO DEEP.

    I suspect that is the problem with one of my plants as well. If you look in the photo above, the berry plant in front of my daughter is large and healthy. There is a second boysenberry planted behind her on the other side of the trellis. It has always struggled. I divided the original plant given to us into two plants. Originally, I thought that I may have damaged the smaller plant when I divided them. Now, I think I planted it too deep. In the fall, when the plant goes dormant, I’m going to did it up and replant it higher. I’ll let you know how that goes.

    Boysenberries also like good drainage. If your soil is very clayey and doesn’t drain well, that may also be contributing to their poor condition. If they are planted in soil that drains well, you can water daily during the hot season. I do.

  3. doug Says:

    Hello I have many boysenberry plants and I have a good amount of fruit but the fruit is small. And the plants dont have much follage. I would like to find out if I need to add more nutrients or if I need more watering. Or both. What is a good fertaliser for these plants. Thank you doug

    • Chris Says:

      Hi Doug,

      I am by no means an expert but, our Boysenberries like the following:

      1. Heat
      2. Rich Soil that drains well
      3. Deep watering
      4. Foliar Fertilizer
      5. Annual Pruning

      To address your specific concerns I would suggest the following:

      1. Excavate the soil down around the roots and replace soil with a mixture of soil and compost. Boysenberry roots are pretty invasive so you probably won’t hurt the plant if you cut into the roots a bit.

      2. Make “wells” around each plant to capture the water and ensure that it drains deep into the root zone. It the water does not drain quickly, you may need to dig down into the soil (as noted above) to allow better water penetration.

      3. Find a good foliar fertilizer that can be sprayed directly onto the leaves of the plants. We like a product called Eleanor’s VF-11. Funny thing, I just checked out their site to make sure that the link was working and noticed that they are using my kids’ fertilizing video on their home page. Cool. Guess I’d better talk to Eleanor about getting some free product in exchange! 🙂

  4. Cyntia Wood Says:

    Can Boysenberries be grown successfully in Centrel Illinois?

  5. igardendaily Says:

    Hi, I just planted a thornless boysenberry today! Afterwards, I came inside to check and see if I did anything wrong…thanks for your great post. I think I have done everything correctly but I love how you are growing yours on a trellis. I put mine slightly in front of a fence so it could have it as some support and protection against wind. Your’s is very attractive, more so than along the fence!

  6. Gloria Says:

    Okay, so I bought some thornless boysenberries last spring and planted them and they bore a lot more fruit than I was expecting. They flourished in the spot we put them…they absolutely love the dryer vent! That said I have been evil and haven’t paid any attention to them since. They need to be pruned I am sure as they are all over the place, but at this point how do I tell the primocane from floracane? Is it too late to prune them? Should I just wait and prune them at the end of the next cycle? Thanks for any advice you can give. Oh, and I live in Los Angeles County to give you an idea of my weather.

  7. Caroline Ferreri Says:

    In looking at your diagrams, it looks like you can space the vines 3 ft apart or 5 ft apart…is one better than the other? We just got 5 vines and are going to put them in pots until we figure out where to plant, and how far apart. Thanks

    • Chris Says:

      5 ft is probably better as it will give more room for branches to spread. Less shading by other branches means more sunlight reaches the plant.

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