Boysenberries bring me back to summer time cookouts with that beautiful dark purple color thick syrup oozing out of the perfectly browned flaky pie crust my mother used to always bake!
When I was a kid I remember a patch of boysenberries out in the back yard, loaded with big boysenberries. I’m sure they never got the ripeness that makes them sweet, because I remember puckering up several times, but who could wait! If only I could have waited until they had a slight softness and came off with the slightest pull. KIDS!
Once I had established a home and a spot (ha ha, temporarily) to grow berries, boysenberries were the first to go in. I put them on the north side of my garden in full sun. This was my first raised bed! With a lot of compost, a little fertilizer and love they flourished. The first year we got a bumper crop! ONE BIG handful. Granted, I did plant in early summer, so they didn’t have much time to produce flowers, but the root system was hard at work. The second year a far cry from the first. We ended up with three harvests the first gave us over 2 gallons. This was off of four bushes crammed together in a space of 2×8. After several years of growing my boysenberries in the garden, I decided to move them to their new home. I started to get runners popping up in the neighboring veggie spots and…..I needed more space for growing garlic! Late full I amended a new spot in full sun in the back of the orchard. Lots of compost, a little peat and plenty of water to get them off to a running start.
Boysenberries love warm weather, and don’t seem to mind the bright sun here in sunny Southern Utah. There are thornless varieties, which I have tried both, but the production has been less for me. Pruning can be a little prickly, but a good pair of gloves will take the bite. Most brambles produce higher yields when staked. I use a simple method of two t-posts on each side of the boysenberry row with three wires pulled between. I keep the flowering vines (last years canes) tied up and let the new canes, which will produce next year, bramble on the ground. You can tie these guys up, but I don’t mind and it makes pruning the right canes later down the road much easier. Once you have harvested your berries and there are no more flowers on their way, cut back the canes that produced. These are two year canes. Tie up the canes that grow this year, 1 year canes. Fan out to make room and if the canes are very long, 8 foot or more, cut them back to six foot to produce side shoots. These side shoots are big producers, so encourage it!
In early spring, just when the leaves start to grow, give them some food. I use an Acid Mix fertilizer because berries do better when the soil pH is on the acidic side. Sprinkle 5 pounds per 50 ft row. Toss three to four inches of compost on. Our soil pH here is high, so I also give my berries a sprinkling of coffee grounds every so often. Once flowers start forming, water more often and deep. Berries should have a nice shiny deep purple color and they should pull off very easy with the slightest tug for the best flavor.
Make a pie, freeze some for winter, sprinkle over the top of whole wheat pancakes for Sunday breakfast! Enjoy the berry season and remember to share with your husband!
Out Standing In The Garden 
I have to hand it to you for being one of the few websites to pass along the correct pruning advice for boysenberries. I even stumbled across an old Los Angeles Times article that perpetuated the belief that one must wait until winter to trim back a boysenberry bush. According to Knott’s Berry Farm, where the boysenberry was developed, the best time to prune is right after harvest. In Southern California boysenberries can appear as early as April or May and so pruning back these bushes in late Fall or early Winter — some 6-8 months after the fact! — can mean a severely reduced harvest. The standard berry pruning advice appears so often on the web that it’s easy to miss the fact that boysenberries perform best when trimmed right after they finish producing for the season. Most gardening websites fail to point out that unlike other berries boysenberries bushes may peak quite early in the summer and will therefore require earlier pruning — unlike other berries that appear much later in the season.