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Removing rusted galvanized raised beds, what to replace with?

 
pioneer
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Our new home came with brand new galvanized steel raised beds. In the whirlwind of renovations and moving we figured we would run with it and the first year went fine. The second year they began showing rust, the third year they are all rusted on the inside, and the produce of those beds was really not great. It is hard to tell how not great it was because it was a really not great year in general, with all the wildfire smoke, but I'm inclined to dump all the soil in the woods, recycle the steel, and start over. What should I replace with?

I have access to a lot of woodchips. The paths are all in woodchips. I have tried BTE gardening and I'm doing something wrong, because there is no compost happening down there, just 12-18" of chips over mineral soil. We have lots of earthworms but they inhabit the beds and borders, and have not been transforming the chips. The oldest chip bed is almost 3yo. I grow plants in it by putting compost into the potting holes and pouring on gallons of compost tea and fish sauce. So basically, I would like to use something that isn't more chips.

I could try bed-shaped mini hugels, but the dirt would wash down the sides. There are zero rocks on the land, so a nice rock border is out. I could build a nice border with logs. We have tons of fir, cedar, alder, and pine that are about the right width to stack for a low border, but I worry about ants. This is probably what I'll end up doing, though. We have almost perfected our toad habitat and they do a great job with the ants and the slugs.

Any other ideas? There are going to be 8 un-beds with un-garden soil in them, about 3' by 8'.
 
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I doubt bushfire smoke will have caused any residual harm to the soil in the beds.
Build up of heavy soot or ash settling from the air can temporarily alter soil chemistry.
from research "
What Happens When Galvanised Iron Corrodes?
• Zinc Coating Breakdown:
Galvanised steel or iron is coated in zinc to prevent rust.
As the metal ages and corrodes, small amounts of zinc can slowly break down and enter the soil.
Zinc is a natural plant micronutrient and is safe in small quantities.
• Rust (Iron Oxide):
Rust is simply iron oxide. Surface rust from the underlying steel does not leach into the soil in high enough concentrations to damage plants or toxicity levels.
• Soil pH Factor:
Acidic soil (with a low pH, typically below 5.5 to 6.0) can increase the leaching of trace elements like zinc or minor impurities such as lead (sometimes found in older galvanised products).
In standard garden soil (pH 6.5 to 7.0), leaching is minimal."
 
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Scaffold boards are worth a look, thick enough to last years without treatment and you can usually find them cheap secondhand. My concern with galvanised in beds has always been the zinc leaching anyway, so going untreated timber at least takes that worry off the table.
 
Kris Winter
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"I doubt bushfire smoke will have caused any residual harm to the soil in the beds. "

Sorry, I meant the smoke blocked the sun and messed up the growth of a lot of local gardens, making it hard to tell whether it was the rust or the lack of sun.
 
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Did you amend the soil in the beds between seasons Kris? I'm suspecting like John C Daley that the rust is only cosmetic and nothing to worry about.

Personally I'd probably just top up with good compost and carry on with the existing beds (but I'm frugal like that). Replacing the beds seems a bit like hard work. Also you can surely buy quite a lot of organic veg for the cost of new raised beds and soil! An alternative is to empty the beds out and tip the soil on the ground. Again top up with some compost to kick start things in the spring.
 
              
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Kris, before hauling all that soil out, I'd ask a soil lab what it would cost to check it. Describe the rusted beds and poor crop growth. A test for nutrients and pH, which measures how acid the soil is, could help with the growing problem.

If your concern is metals from the beds, ask about that as a separate question. A routine test for plant nutrients is not the same as a test for metal contamination. Oregon State Extension explains that the test method changes what the results can tell you. The lab can help choose the right test before you send soil.

One useful detail from its sampling guide: don't use galvanized tools to collect a sample for zinc testing. Follow the lab's collection instructions.

Testing guide: https://extension.oregonstate.edu/catalog/pub/ec-1616-reducing-lead-hazard-gardens-play-areas
Sample collection: https://extension.oregonstate.edu/catalog/ec-628-guide-collecting-soil-samples-farms-gardens
 
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My first thought is that the soil in the planters might not have been good.

I would suggest starting to add organic matter to make that soil better rather than dumping it.

Fall leaves, wood chips, grass clipping, veggie scraps are some example of organic matter.

And as Nancy suggested topping it all off with some compost and then feeding with compost tea.
 
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I would keep that soil and give it a second chance before hauling eight beds out to the woods. I had a similar rusted bed at home, and most of the problem turned out to be tired, low organic matter soil rather than the metal itself. I would mix in about 3 to 4 inches of finished compost across each 3 by 8 foot bed, then plant a cover or a heavy feeding crop and feed it with compost tea every two weeks through the growing season. For the border, I would go with your log idea. I have used untreated cedar logs stacked two high, about 8 to 10 inches tall, with the ends pinned by short stakes, and they held soil well without washing out. Keep the logs a few inches away from the woodchip paths so they stay drier, and leave small gaps at the corners for toads to come and go. That mix gave me steadier moisture and much better growth the next year.
 
I agree. Here's the link: http://stoves2.com
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