A storm, winds heavier than usual, and the weight of a good crop brought part of the support structure for the only two kiwi plants in the farm down to the soil. Kiwi is a new cultivar here.
A new structure is needed. It must support not only the weight of the crop but tension that could be carried over by strong winds: when the kiwi plants grow, stems and leaves form an almost homogeneous cover that offers resistance to the wind as a whole and thus acts upon the frame.
There are several solutions. Metallic or polymeric bars could be intercrossed and fastened. In fact steel bars formed the previous frame. However there are not low-cost ready-to-use easy-to-install products available. Timber offers less durability. Given the know-how and tools at hand I regard any of the materials as equally time-consuming.
Concrete offers a more resistant frame, good performance and longer life-span. I would not consider it if there were many plants, as transport, time and difficulty of construction would favour any of the previously mentioned materials: even if not as much resistant, they are effective enough for what uses to be even the most common heavier winds of the area. And once the frame is set up, if replacement units are left, it would be easy to mend or to replace if any element got damaged.
I prefer stone as a visible surface in this environment. There could be polymers, even steel bars with much more thinner section, that offer less visual impact than concrete, however they lack the appearance stone or wood show. Anyway the plants are going to hide most of the frame, and thus any aesthetic features of the frame itself would be minimized. As far as I have seen in traditional vine supports, squared stone is used for the posts. In terms of shape the most similar appearance would be that offered by concrete. More: I can favour a rough look more similar to that of stone avoiding a release agent over the shuttering. Texture remains that of concrete. However, even if it could take some years and does not hide concrete appearance completely, roughness rises a microhabitat for moss to grow in these rainy lands.
Anyway I can apply a finishing if needed. In fact some buildings of the farm require to be covered with stone.
Suggestions about concrete and finishings over concrete are welcome.