Arbor for Kiwiberry

I planted 2 Kiwiberry "vines" which will need a support to grow on. I do not want to put pressure treated lumber into the same ground I grow food. I was thinking about setting a 4" steel post base into concrete (something like this). Then I would use non-pressure treated lumber and when it rots it can be replaced more easily since it is not into the concrete. I plan on the posts being 12' tall. 3 in total and would be connected together at the top. Do you think these post bases will support such tall posts? Any better ideas? Am I being silly worrying about pressure treated lumber in the first place? thanks

 

I think it's a good idea not to use pressure treated wood near the food. At the same time, you won't have the support. How about a 4x4 cedar post?

4 in. x 4 in. x 8 ft. Rough Green Western Red Cedar Lumber-635251 - The Home Depot

The one in the pic is 8' tall but I'm sure you can find something taller at a lumber yard, if Home Depot doesn't have it.

 

Posts alone will not hold up kiwi. I have 4, plus a male and they grow so fast and big you have to brace off the posts with either interior angles or cabling to the ground behind them. They are super heavy. A 12' high arbor will be too high for you to trim the kiwi effectively. Kiwi will tend to wrap around itself and choke itself to death, so you have to unwind them and trim the "wrappy" ends off.

I have mine on Black Locust posts with #9 wire loomed on cross arms and braced off with subterranean ground screws with eyelets and take up ratchets. They must be trimmed each week, and cut back in the winter.

Pressure treated posts pose no threat to the food source. That's a scare tactic from your local organic gardener's club. You won't be changing any posts once the kiwi take over, so make them as permanent as possible.

 

Chandler, I have a couple of questions. Did you set your black lotus post into a cement footing? How tall are your post? Thanks

 

Posts are 6' above grade, and 2' below, not concreted in, approximately 9"+ in diameter. I am not relying on the ground to hold my posts at all, but the suspension bridge built by the #9 wire up and over the posts and racheted tight. Posts just determine the height, not the strength.