The only downside to the cattle panels is that they are galvanized and that contains zinc, lead and cadmium. They say it's safe to use for plants, but galvanized products for water can be toxic because those metals will get into the water. I imagine it can be the same regarding plants since they uptake water. Lots of people use the galvanized stuff for gardening, even for raised garden beds. In my opinion the article below contradicts itself in this way, but maybe I'm wrong.
Lead and cadmium:
"The zinc in the galvanized steel also contains lead and cadmium metals. These metals are added to the galvanized steel during the manufacturing process.
So, these metals will get mixed in the water if you use galvanized steel in the water pipe. So, the water can be poisonous for use of galvanized steel.
Deposits of galvanized steel:
If you use galvanized steel for food storage, cooking, or water container, the deposits will release in the food and water. This will cause poisoning in humans and animals.
Is it safe to grow vegetables in galvanized steel?
Yes, it is safe to grow vegetables in galvanized steel. Galvanized steel is safe to use for gardening.
Generally, galvanized steel contains zinc metal. Zinc is a natural constitute of soil. Moreover, zinc is pretty essential for the growth of plants. So, if you grow vegetable plants in the galvanized steel, the zinc in galvanized steel will not do any harm to the plants.
Moreover, if the zinc is released from the container of vegetable plants, it will be helpful. Moreover, zinc has little or no effect on vegetable plants. So, using galvanized steel for growing vegetables is safe".
https://onehappylemon.com/is-galvanized-steel-toxic/