Hi,
we have a beautiful blackberry. Thornless with big black fruits. But it is completely unruly. Previous tenants have made blackberry area with metal rods and some string, but this blackberry is too vigorous for it and has actually broken some of the rods. So, in order to be able to pick the fruits and also to pass without getting a blackberry cane in the eye, we spruced it up with a blackberry trellis. 🙂

Needed things for blackberry trellis

4 x 160 cm 7 x 7 cm pressure treated posts (this is approx 3 by 3 ” posts that are approx 5 feet tall )
4 x 7 x 7 cm post base spikes (3 x 3 ” )
8 x nut & 8 x bolts that accompany the base spikes
30m (100 ft) 2 mm (approx 1/8″) diameter steel rope
12 x steel hooks
6x turnbuckles to tighten the steel rope
12 x steel clips

you will also need a drill with drill bits that are in 2 sizes – the size of bigger bit is the size of the bolts and the other bit size is slightly bigger than the diameter od steel rope.

Here is the video and further in post you have all steps described in detail.

Step 1 Tidy it up

Start first by tidying the area. remove as many weeds as you can and also remove all dead and dried or third-year-old growth of blackberries. Then measure the area to make sure where you will put your posts. Also tye the blackberry branches so they don’t get in the way.

Step 2 Prepare the posts

We decided to use a system that is used in the wine yard. This is how my grandpa would make his posts for the wine yard – the only difference being in material (grandpa would use concrete).

We will start by marking the post base holes on the posts. Mark both posts and post bases with the numbers 1-4. Then put the post base on the post with the same number and mark the holes on both sides of the post. Remove the post base and drill the marked holes in the post using the drill bit in the correct size.

Next, we will mark the holes where our steel rope will be anchored or drown through. First and last post (posts 1 & 4 in our case) will have hooks, while middle posts (2 & 3 in our case) will have holes drilled through them. The important thing to remember is that posts 1 & 4 will be mirrored. So the hooks on post 4 should be set in a way that they product mirror image of the hooks on post 1. Here is a little graphic to illustrate it all.

For posts 2 & 3 it is only important to put them in the same direction since the holes will be drilled through. They have holes in the same spots.

The pattern for blackberry trellis

Both holes and hook will be put in the same fashion. The first hole/hook will be 10 cm (4 “) from the top of the post) and 2,5 cm (1 “) from the side of the post. The next hook/hole will be 5 cm (2 “) lower than the first one and 2,5 cm (1″) from the other side of the post. The next set of hook/holes will be 40 cm (approx 1′ 4”) from the lower hook/hole. This pattern will be repeated one more time on the post so we have 3 sets of 2 hook/holes on one post.

When you have marked out everything, check one more time that all of the markings are correct. Then drill in the hooks on posts 1 & 4, and drill the holes through the posts 2 & 3. And you are ready for assembly!

Step 3 Putting post in their spots

Using sticks and rope (or better laser) mark the straight line which posts will follow. Then start by adding the post bases with correct numbers on the approximate spots. The distance between the posts, in this case, should be min 1m (3 feet) and max 1.5 m (5 feet). We chose to go with 1.3 m (4′ 3″ ) between the posts. This should be able to withstand the weight of the blackberries.

We then determined the highest ground point and proceeded with pushing the post bases into the ground. These post bases have long spikes on the underside that are anchors in the ground, so you don’t have to use concrete to anchor the posts. We managed to push them in, but if your ground is too hard or has some gravel in it, you may need to hammer them in. You can also buy a special insert that allows you to hammer the post bases more easily.

To make sure our posts are leveled, we used a level to level the post bases. When we were happy with how deep the post bases were and their level, we added a bit of dirt around the post bases to make them a bit more sturdy.

Then we added the posts to the post bases and screwed them on using the nuts and bolts. You can take a little break now since the next part will be a bit tedious.

Step 4 Stringing the steel ropes

Now that the posts are in the ground we can string the ropes between them. Start by measuring the ropes and cutting them to the size. Then make a hook on one side. This will be the side without a turnbuckle. Do this for all of the ropes.

Then hook the ropes to the first end post. And thread them through the posts with the holes. When this is done, add the turnbuckles on the other end of the rope. Make sure that the steel ropes are tight enough but also relaxed enough so you can remove them. Then tighten the ropes with turnbuckles. And you are ready to tie the blackberry canes to the trellis.

Tips and tricks for building blackberry trellis

Here are some tips and tricks that will allow you to make a better blackberry trellis.

1. angle & anchor your end posts – we made a mistake of adding our posts vertical to the ground, but now we have to anchor them in order to stay upright. There are ways of anchoring them even if you have put the upright, but they will need an extra pole before them. Even if you angle them so they point outwards, you can still anchor them by using a rod anchor that you can push into the ground or use concrete to add a hook to which you will then anchor the posts
2. make sure your turnbuckles are completely released before you measure the steel ropes – otherwise, you won’t be able to tighten them
3. have a mallet or big hammer handy – we did manage to push our posts without the use of the hammer, but, depending on your soil, you may need to hammer them in.
4. tie the canes after everything has been finished and ropes are tightened – this system also allows you to push the canes through the two wires more easily. stabilizing the canes and preventing them from going all over the place. Use it.

Conclusion

In this post, we have shown you how to make a blackberry trellis that is reminiscent of vineyard trellis systems. Make sure to read the tips section and stay tuned for updates, since we will also be adding some anchors to the system and a raspberry trellis as well.