How to Install a Raspberry & Blackberry Trellis
My old raspberry and blackberry trellis was made of green ‘T’ posts and light gauge green wire. Not particularly attractive, so I decided to install a more professional looking trellis. I just moved my raspberry and blackberry canes up against my fence, so I already had one side of the trellis taken care of. The other side, I decided to install a standard two wire system held up with 4x4 wooden posts. This system works well, looks nice, actually it is hard to even see, and is easy to install. If you do not have a fence you wish to install your raspberries against, you would simply need to install the two wire system on both sides of the canes. This would actually make it easier to pick raspberries on both sides of the trellis. I will be forced to pick from one side only, so I will probably miss some berries. That’s OK with me, we always have tons.
12.5 gauge orchard wire
6 foot 4x4 pressure treated timbers
Gripple tensioning tool
Post hole digger
1. Install 4’ high 4”x4” pressure treated timbers as fence posts no further apart than 50’. These timber posts should be 6’ high timbers that are buried 2’ into the ground so only 4’ is exposed. Also, it is a good idea to put 4” of gravel at the bottom of the hole and tamp the gravel, so you would need to dig 28” deep fence post holes.
2. Drill holes at 18” and 36” in fence posts to install the wire at different heights. This can vary by a few inches. For example, my end posts had only the two holes drilled, but my middle posts had four holes drilled, so I had to place them down a couple of inches so as not to interfere with my other drill holes. I drilled once, just large enough for the 12.5 gauge orchard wire all the way through. Then I used the same hole to drill just half way through, but much larger to fit the wire vices. This only has to be done on the side you will install the wire vice.
3. Cut the wire to fit between your timber posts, leave at least 3’ of extra slack.
4. Thread the wire through an end post, and into the skinny part of a wire vice. Pull through so you have a foot of slack. Then thread the wire to the connecting post and connect to another wire vice. Hold the wire vice down by hand or with screws and pull the line taut. Use the gripple tensioning tool to get the wire even tighter. Cut the excess if you have more than 1 foot. Make sure to leave enough excess to re-tighten as needed. I like to leave about a foot of excess.
5. Repeat step 4 for all of the wire that you need to install.
6. If you have long runs like I do, you can install one ‘T’ post in between your timber connecting posts to hold the wire up better so it looks nice.