No.

But if you stain the outside with a waterproofer, rather than the inside you may be trapping moisture in the wood because it won't be able to 'breathe'. The inner side will get wet from the soil but the water will have no escape route.

Is staining both sides a bad idea?

How about if i just use normal paint on the outside? That ok?

There are eco-safe sealers, stains and waterproofers that are perfectly safe to use with edibles. Most of the box stores will carry a selection.

Agree about the effect on wood mentioned above.

I have no idea what is in the Behr stain you have but staining the outside of the wood isn't going to contaminate your soil in anyway and that was your question. Even using it on the inside of the wood poses no realistic problem for your plants.

But there are always a few who want an unrealistic 110% guarantee against leaching chemicals and they will assure you that using it will poison your food as the plants "suck up all those toxic chemicals". Note they don't understand how plants work or worry about what is in their soil just the things that come into contact with it. So if you want more assurance then go with one of the eco-safe sealers.

Dave

In this context, it should be pointed out that wood itself can be pretty toxic. Yep, no kidding. It can be a serious irritant and allergan. Wood dust is linked to athsma, headaches, respiratory disorders, and stomach cramps. Of course, one can imagine that this toxicity is absorbed by plants, such that plants grown in a wood-lined bed are POISON. Gives you shudders just thinking about it. Gee, maybe you should apply sealer to keep that evil wood stuff away from your plants. Western red cedar is considered to have high potency in this regard.

I think I’ll go for this one, thanks for the replies everyone!

https://www.homedepot.com/p/TriCoPolymer-VOC-Free-Non-Toxic-Lumber-Seal-1-gal-Clear-Satin-Wood-Sealer-LS128/203322573

Do you have to have a sealer? You can get stains which don't seal and that would avoid the rotting problem with trapped moisture. Satin would give you a slightly shiny finish which seems a bit artificial for outdoor woodwork.

But won’t sealing both sides make it waterproof? Good point about the satin. I’ll check out some others.

I'm not sure what the concern is......waterproofing the wood used in a raised bed is not a bad thing! In fact, it is often a desired intent. Raised beds are made from a lot of things that are far less water permeable than wood, even waterproofed wood, and they work just fine. Proper drainage occurs when you use a decent soil mix and there is not a solid bottom to the bed........just by virtue of the elevation involved.

I'm not one to do a lot of staining, painting, or other types of wood preservation, but I wonder what vegetable oil mixed with espresso grounds would look like? Another natural source of dye that might be useful are the husks of black walnuts. In my thinking (admittedly deficient,) there isn't anything in such materials than would be present in nature. I use walnut oil to seal a food prep table I have... works well, but would be expensive if that was the oil used for your purpose. Besides, you aren't worried about the rancidity of veggie oil, you're just looking for a 'safe' preserver from the elements, and a bit of cosmetic sprucing.

Oh, and linseed oil is another time-tested, relatively inexpensive, natural sealer that's known for its relative longevity. If you use these plant-based oils, my thinking is you could seal both sides of the boards, but remember, natural sealers don't last as long as some of the synthetic ones.

gardengal, the problem with not sealing all sides of the wood is that the moist side, that is: the side facing the soil, will never dry out because the air-facing side is sealed. The wood will always stay wet, and you'll be inviting rot. Pressure-treated wood holds up better, but sealing just the air-facing side will reduce it's expected usefulness.

Supposedly, one is sealing the wood before any contact with soil and soil moisture. And since most purchased lumber is at least air dried if not kiln dried, there is minimal moisture that is being sealed in.

This is not a revolutionary concept!! Many raised bed gardeners seal the wood used to construct their beds, both inside and out. Sealers will help prolong the life of the wood, not accelerate any rot!

GG, sealing all sides is not a problem. The issue was the original idea of sealing just the outside of each plank. My contention stands that this would trap moisture in the wood.