# Building first trellis



## nicklausjames (Jul 23, 2015)

I live in upstate NY about 2 hours north of NYC. As such the climate is humid in summers and cold and snowy in winters. Anyways I'm building my first grape trellis and I plan on planting chardonelle grapes.

I purchased pressure treated 4 x 4 wood end posts. They are 8 footers. I used a post hold digger and was able to dig down 30 inches. Will this be deep enough? 

The end posts are 20 feet apart on a slight hill. I will use intermediary metal posts in between to add strength. 

My question is is the 30 inches deep enough? Also do I need to fill the hole at all with gravel or concrete or just fill it in with dirt. I also plan on tying the end posts back with metal anchors that twist into the ground.


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## nephils (Jul 23, 2015)

nicklausjames said:


> I live in upstate NY about 2 hours north of NYC. As such the climate is humid in summers and cold and snowy in winters. Anyways I'm building my first grape trellis and I plan on planting chardonelle grapes.
> 
> I purchased pressure treated 4 x 4 wood end posts. They are 8 footers. I used a post hold digger and was able to dig down 30 inches. Will this be deep enough?
> 
> ...



As far as I have read...the depth of the end post should be 3' - 4' deep if using earth anchors and if the rows are less than 600' long, depending on your soil (lighter = less length at that depth). I don't know anything about concrete or gravel, but I assume it can be filled with dirt.


This links to a very good presentation. http://viticulture.hort.iastate.edu/info/pdf/domototrellis.pdf


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## RedSun (Jul 23, 2015)

You did not say how long the row is. And you did not say what trellis system you'll be building.

In general, the end posts should be stronger. The 4x4 is not really 4"x4", but thinner. You better use stronger end posts. In general, you bury about 3' in the ground. So this leaves you only 5' above ground. If the end posts are installed at a proper angle, then you'll have just about 4' above ground. You get the picture.....

From what I know, gravel is not recommended. It is easy for the gravel to shift and move than native soil. Concrete is stronger, but I remember a lot of people are against it and I forget about the reason. So I only use regular soil....



nicklausjames said:


> I live in upstate NY about 2 hours north of NYC. As such the climate is humid in summers and cold and snowy in winters. Anyways I'm building my first grape trellis and I plan on planting chardonelle grapes.
> 
> I purchased pressure treated 4 x 4 wood end posts. They are 8 footers. I used a post hold digger and was able to dig down 30 inches. Will this be deep enough?
> 
> ...


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## bchilders (Jul 23, 2015)

nicklausjames said:


> I live in upstate NY about 2 hours north of NYC. As such the climate is humid in summers and cold and snowy in winters. Anyways I'm building my first grape trellis and I plan on planting chardonelle grapes.
> 
> I purchased pressure treated 4 x 4 wood end posts. They are 8 footers. I used a post hold digger and was able to dig down 30 inches. Will this be deep enough?
> 
> ...



Hi Nick, it sounds like your rows are 20' long. That is short by most standards so a 4x4 might be OK but a 4x6 or 6x6 would be better. I use 6 to 7" round post 9' tall and my rows are 100' long. For my shorter rows, around 25', I use 5 to 6" post 8' tall. I try to sink all my posts 30" if possible and I have not had any problems. The main thing about depth besides row strength is to get below the frost line. Use dirt to pack with as it packs better and will not heave up out of the ground as bad with a freeze like concrete tends to do.


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## sour_grapes (Jul 23, 2015)

There are various "grades" of pressure-treated wood, ranging from "above-ground use" to "ground contact," "Foundation grade," or "marine use." If your posts are not rated for ground contact, they will surely be toast within a few years.


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