Cost vs Benefits of T Trellis vs. I Trellis for Berries

I have a long berry row, about 125 feet long, with a bout 12 raspberry and 10 semi-trailing blackberry plants. Now it is time to install the trellis for them.

Thinking about either the wood I trellis, or the T trellis. I do not know if the benefits from the T trellis is worth the extra cost and efforts.

Questions to ask yourself:
Which one will be easiest to grow with, harvest, weed, spray, etc.?
Will the one you choice be economic over the life of the patch?
Sometimes extra work at the start will be rewarded with long term results that are the most satisfactorty.

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I went to a lot of trouble and expense creating trellises w/cross bucks out of treated wood for my grapes, raspberries, and blackberries and am very disappointed. I can’t get the posts to last but a few years. All my newer berry plantings are done with t posts. It is also a whole lot easier putting in t posts than using a post hole digger with all of the wooden 4 x 4’s. I do endorse using the plastic coated clothesline. It has held up extremely well and can be bought cheaply by the spool in many hardware stores.


What are the differences of your cross-bar trellis vs the T posts? Is the T post be cross bar? Just not sure.

I believe the term T-post refers to the generic metal narrow field stakes, usually painted green, some with flukes on one end to aid in pounding into the ground.

It looks like a few of them are in your picture above.

With a caneberry row that close to an existing fence, I would not use any cross-bar system, you need all the room you can get to squeeze between the berries and the fencing when pruning and harvesting.

The trick will be to tension the trellis wires without pulling the stakes out of vertical. Use some bracing on the posts at each end or use very heavy-duty posts at those two locations to attach the horizontal trellis wires.

Got it. The T posts are just some metal posts. They are used in I trellis, without the cross bars.

The cross bars certainly give the plants more room to grow. And we can separate the primocanes and floricanes. But the cross bars have to very strong at the ends. I figure some earth anchors are needed.

I saw this youtube video and I’m going to try it on my blackberries soon. This winter I set up a similar setup for my Southern Home Muscadine. Not sure if it’s minimal design is right for everyone but the cost will be hard to match. This guys voice could fit in with most any of the southern states. Bill

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That creates a narrow row that would work for Red Sun. I’m sure people who have a crossbar system put it to good use, but I have not seen that system used here in commercial or u-pick fields. My short crossbars have been somewhat of a nuisance, because new growth gets outside of the wires without constant inspection. I end up tying all canes to the main posts or to each other, the thinner trailing types end up on the crossbar wires.

I watched most of the video and that fellow is already tweaking his system and voicing concerns. He put the trellis up after the plants were grown, that is the only way the plants are now spreading the wires. With a variety like Triple Crown with its heavy fruit load, much of that row would go sideways. Of course caneberries can be heavily pruned so they are not so massive.

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Below is a useful link on trellis design

I’m inclined to do the trellis with wood crossbars. Extra work, but much more expected yields.

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Apparently the response from my phone this weekend didn’t make it. A wooden trellis with cross bucks will cost at least $10–a 6 ft 4x4 treated post, treated 2x4, and 4" stainless steel wood screws. I also use 4 turnbuckles and eye bolts, which cost adds another $20 per row. A 6 ft t post costs $3.40, but twice as many are required if you surround your planting. My treated posts aren’t lasting 4-5 years before they’re breaking off at ground level–then again, we’ve had exceptionally wet weather overall. They are a huge pain to replace especially when they’re in the middle of a 200 ft row. Additionally, some of the cross bucks are pulling away from the posts. A t post will last much, much longer before eventually rusting out. Wooden posts are much harder to set as opposed to simply pounding in t posts. With raspberries, wooden posts are overkill and even so with erect blackberries if you keep them pruned. However, with semi-erect and trailing blackberries and grapes, you might be more satisfied with the sturdier wooden posts. Maybe someone out there knows a secret to getting more life out of wooden posts. If so, I’d sure appreciate knowing.

Hey Brook, I think I’m a little slower than the average bear, but could you please explain in a little more detail how you employ the metal t-posts. Specifically, what do you use between the 2 (or more) posts in a row to actually hold up the canes. You mentioned the plastic coated clothes line…is that what you use to connect your posts and hold up your canes? If so, how do you connect that clothes line to the t-post. Last but not least, if you run one row of t-posts connected with some kind of wire (maybe the clothes line) to support the canes, what keeps the canes from falling the other direction? Do you actually run 2 rows of t-posts connect with wire on each side of your canes?

My husband is in the works of building our trellis systems for blackberries, bosenberries, loganbarries and raspberries. It may be a bit beefy but that is how he builds things :slight_smile: ! He used 1/8" stainless steel cables with eyelets and turn buckles. 4 x 4 posts are cemented in the ground with the cement mounded at top to help with the wood decaying at the soil line.


CCA treated fence posts will last a long time and work great on a trellis. The 4X4 post at the building supply are made for above ground use and do not last long when in direct contact with the soil. They are not suggested for post on a trellis

I used cedar post on my first blackberry trellis a long time ago and the smaller posts rotted in a few years just like the 4X4 PT posts

Here is a picture

of my current trellis. Its been in the ground 5 years and is in excellent shape. The rows are about 400 feet long and the posts are CCA fence posts. The T are PT 2X4 with two 3 1/2 inch screws. Tension is provided by Gripples against the “dead man” at each end.

The trellis supports a lot of weight! At 15K pounds per acre, each 400 feet of trellis row holds up more than a ton.


Wow, Puggy! you are one lucky girl! And again the neatness is fantastic. Not easy to keep up with. Wait until your bushes are exploding with fruit. You’ll be in heaven!

blueberrythrill, this is very nice looking.

Beside my berry row, I have three rows of grapes, all about 125’ long. So the berry trellis is just a start.

For the end posts, I’d like stronger posts than the typical 4x4 treated posts. Still not sure where I can get those posts. The good thing is that, I only need two end posts each row. Then the 4x4 treated posts can be installed in the middle. Earth anchors will be used to hold the end posts. For the berry row, I may be able to get away to use the 4x4 as end posts too. Just do not want to rebuild the trellis again in 5 years.

The chemicals for treating lumber changed about 10 years ago to improve safety. Not all PT lumber is the same. Be sure to use something designed for ground contact so they will not rot in 4 or 5 years. The CCA fence post like I used work great on a farm, but they may not be the best for use in a residential setting because of the chemicals used to treat the post.

Looks like you have a lot of trellis to build! Locust post are available in some places. They last a long time. 4X6 post treated for below ground use would last a long time, but are expensive. The CCA post are available at farm supply stores and are reasonable in price.

rick, my system is identical to yours only I have the turnbuckles, not Gripples—and mine aren’t nearly as clean as those beauties. I have 4 rows@ 200ft long and a smaller row of part black raspberries and Black Satins. I didn’t know you could still get CCA timbers. I do get mine at our local farm supply (Rural King), but I’ve also gotten some at Menards. I also misspoke and called the 4x4’s 6ft when they’re actually 8ft.

Kevin and Red Sun, I have several different varieties of blackberries, and the erect ones (Black Satin, Ouachita, Prime Jim and Jans) really don’t need much support. I place t posts on both sides of the row and use the coated wire at 2 different heights. I wouldn’t mind trying the heavy plastic twine, but I have lots of clothesline wire on large rolls. Keeping tension is a little harder on t posts, but I don’t mind a little sagging–good thing, considering my increasing age. However, varieties like Triple Crown benefit from stronger support. Grapes definitely require a beefy trellis. Red raspberries don’t need much support at all. I have my black raspberries though on both wood and t posts.

Puggy, your system also puts mine to shame.

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If you want wooden posts to last for decades in a wet climate, place coarse rock at the bottom of a deep hole and cement the post in, then smear a line of caulking where the top of the cement meets the wood post.

My berry trellis metal t-posts of 18 years are still solid.

Caneberry variety, climate, and pruning methods dominate the crop yield, the trellis structure has little effect.


I don’t know what material a person could use that would last longer than the metal t-post. I’m starting to use these for blackberries and muscadines.