I train my Doyle's thornless blackberries on wires spaced about a foot apart between 6 foot tall 4x4" posts. This has worked well for me.

tcstoehr:

The growth pattern of Doyle is exactly the same as Triple Crown, and they are treated the same way; tipped at 6-7 feet, and the laterals pruned back to a reasonable length on primocanes. I grow both of these berries on separate trellises, and you cannot distinguish between the two except when they set berries. At that point, Doyle has much larger berry panicles and produces about 2 weeks longer than TC.

Wherever you heard that Doyle is somehow different, I can assure you beyond doubt that it is bunko.

After you set your 4x4 posts for your trellis, screw a couple of 2x4's across the entire span of the top. You will need 12 foot or 14 foot 2x4's for this job, preferably treated. I wouldn't go longer than 14 feet. Screw the wood together in a "T" form, and screw the ends into the tops of your end posts. Use long deck screws. This will keep your trellis from pulling together with the tension of the wires and the weight of the canes. Ideal height for the top of the trellis is about 6 1/2 feet, so if you start with 8 foot 4x4's you will be burying them 18 inches.

Use heavy, No.9 wire for supporting the canes. Spacing the wires a foot apart up the trellis is triple overkill. You need only two wires; one at about 3 feet and the second at about 6 feet, close to the top. Drill holes in your end 4x4's with a long, jobber length drill bit. Any more wires than that are unnecessary, and they simply get in the way as you are trying to weave your canes through them to pin them up with twist-ties. I initially started with 4 wires, but reduced that to two when I figured this out. No need to repeat mistakes I have already made.

A trellis built this way will last more than 20 years.

Don Yellman, Great Falls, VA

Good, that's what I'd hoped in general. I'm still hoping to use T-posts instead of 4x4's though.

Don,

What do you consider a reasonable length to trim the laterals and can you trim them anytime? I have quite a few laterals on my first year Triple Crowns which are touching the ground.

Thanks,

Mark

Mark:

I think 3 feet is about right, but it depends on how crowded your trellis is, which, in turn, depends on how many plants you have per foot. Rather than try to give you a precise length for laterals I would just say: Don't overcrowd your trellis. If your laterals overwinter successfully, they will produce berry panicles along their entire length, but as they do they will become smaller and produce smaller berries if not controlled. After a few years of experience, you will find the right point for your particular planting, given your soil and sunlight conditions.

Laterals that touch the ground will often tiproot if the ground is moist. Fine if you want to produce additional plants, but not much use if you don't. Yes, you can trim trailing blackberries at any time during the growing or dormant seasons. Timing does not seem to affect them at all.

Don Yellman, Great Falls, VA

Thanks Don. Most of my laterals are touching the ground so I will go out tonight and do a little trimming. I am trying to tiproot one plant as I have space for one more plant in my row. I am really impressed with how fast and how thick the Triple Crown plants have grown. I've also planted raspberries, strawberries and tomatoes this year and the TCs have shown the best growth by far.