Vegetable safe stain or sealant.

[jbockenfeld]

I am wanting to stain some homemade wooden planters. Any suggestions for safe stain as they are for strawberries would be great. Thanks

[imafan26]

There are many products now made that will be less toxic and are safer.

Most people recommend just using naturally rot resistant wood like redwood or cedar. They will still rot but it will take longer than other woods.

Pressure treated wood no longer use arsenic as a preservative, but it still contains chemicals and it may take years to learn if they make a difference.

Linseed oil is the old standby but it takes a long time to dry.

https://www.gardeners.com/buy/eco-wood-t ... 9-730.html

[pepperhead212]

Almost all clear wood finishes are safe, as many of the things that made them unsafe, such as heavy metal dryers, are no longer allowed. And once cured, even finishes with mineral spirits, such as polyurethane, are safe, as the spirits have evaporated. Stains vary - you'll have to check the individual brand. Here is a link to a discussion on food safe finishes:
https://www.woodcentral.com/articles/fin ... 497a.shtml

One thing you may want, which is not usually considered food safe, is something like a marine varnish, as they have UV inhibitors added. However, as long as it is fully cured, the UV inhibitors really shouldn't pose a problem, as they are basically enclosed in plastic, and these kinds of things are usually only considered a health threat in something like a chopping board, or a bowl, which may wear off into the food you eat. In a pot, you shouldn't have to worry about it.

[jbockenfeld]

What about lining the inside with polyethylene sheets like drop cloth? They say hdpe is non toxic.

[MrBote]

Perhaps line it with pond liner plastic since that's what many of the aquaculture guys use on their wood frames, or that heavy black 6 mil or 9 mil black plastic. The problem with a separate barrier is that if it is allowed to get wet between that and the wood, there may be an anaerobic condition that causes another kind of rot that is likely worse than if the soil was allowed in contact with the wood.

I used primarily, Western Red Cedar for my salad tables, and it holds up for years with nothing on it. At the end of every growing session, either remove the dirt or move it to the middle and let it dry out in between. I think if I were to make something more continuous/permanent use, I would make a wood box that a plastic container fit into. Then you could seal the wood with something like CPES and have it look new for years without concern for toxicity.

I know epoxy is essentially non-toxic once cured, so, perhaps a wood composite approach may be the answer if you are thinking long term. It just has no resistance to UV, but that wouldn't matter on the soil side. On the exterior, minwax captain spar varnish is hard to beat for renewable, resilient coatings, and will provide UV protection over epoxy.