Amy,

This is NOT authoritative. I have been informed that pressure treated wood is, and has been for some time, toxic substance free.

Many years ago it was impregnated with formaldehyde and other toxic chemicals.

Please correct me if you find I'm wrong.

Johnny

One of the posts I lost said they quit using arsenic in 2003. However, home depot lists some chemicals in pressure treated wood. I didn't pay attention to what they were because they weren't arsenic :) I actually thought that NEW pressure treated wood was supposed to be safer than painted or chemically treated wood, but I have no evidence to support that either. My new asparagus bed sits next to an old privacy fence, which could have used pressure treated posts (pre 2003). I'm not too concerned, but ticked off that I couldn't find any decent info one way or the other.

This showed up in my facebook feed, and it DOESN'T include asparagus! 5 foods that can be high in arsenic

This type of mistaken identity (species) is not unheard of within the blogosophere. The real solution would be soil testing or you could pay high dollar for the scientific journal annotations regarding clinical studies performed by trained scientists that are usually careful to avoid these types of mistakes.. At least arsenic would be easy for a soil lab test.

I believe the statement in the book is inflammatory too, and likely is highly exaggerated or perhaps it resulted from the author or a source he consulted confusing the ornamental asparagus fern with the edible asparagus plant we grow and eat. You cannot believe everything you read in a gardening book (or on the internet). I've read lots of garbage in gardening books (and on the internet) that just makes me roll my eyes. I think the reason you aren't finding the definitive info you are seeking on the internet is because this asparagus-arsenic link is a non-issue. With all the research done on heavy metals in soils and the risk they pose to consumers when taken up in foods, if there was an arsenic issue with asparagus that would affect the average person, we'd know all about it. Arsenic is present in our soils and in our water and in our bodies. I'd be far more worried about the arsenic in rice than in asparagus, and I'm not overly concerned about the arsenic in rice, by the way.

We only have used untreated lumber in our raised beds because of the CCA-lumber issue which still was a big issue at the time we moved here and built the garden. However, last year we used some of the current generation of pressure-treated posts to build our new entry arbor to the front garden, and I was not the least bit concerned about using the types of pressure-treated lumber available nowadays. I may even use it in the next raised bed we build.

If you're really concerned about arsenic leaching from your neighbor's fence posts, you could get the soil tested and either find relief from your worries, or maybe it might cause you to put in a new asparagus bed elsewhere.

Many soils in this country are heavily contaminated with heavy metals, unfortunately, and most people show traces of many heavy metals in their bodies when tested. It will drive you crazy if you dwell upon it.

They built the houses in this neighborhood on a cow pasture in the late 70s. I doubt there is TOO much contaminaton, though the side yard by the drainage ditch could be. But asparagus ison ofher side of the yard. I'm not going to worry about the asparagus. We are adding soil to a raised bed. I am more concerned about drainage in this spot. Meh, I grew the plants from seed, so not too much invested if they don't survive. I just have to convince my husband to leave the bottom open. He likes weed cloth and chicken wire in the bottom of beds. (Yeah, I know it's not small enough mesh to keep out voles.)

We just built two new raised beds with treated lumber which I had refused to use before but don't worry about it now. Insecticides scare me much more.

Amy, I left the bottom of the asparagus bed open and didn't line it with hardware cloth to keep out the voles and have not had any vole issues in it, even though they have tunneled into the pathway between the asparagus bed and the potato beds lined with hardware cloth. My main fear was that Johnson grass would come underground and grow up through the hardware cloth and would be hard to remove. I do get minor infiltration of that bed by Johnson grass at the eastern corner of the asparagus bed, but I just dig it out when it pops up. I don't know if I could dig it out if we had lined that bed with hardware cloth because it would have grown up through the hardware cloth.

It could be that the voles didn't find the asparagus bed in its first year when the roots might have been manageable for them in terms of eating. Now that the bed is several years old, its roots likely are an impenetrable mass that they wouldn't be able to devour, so I think that your asparagus will be fine in an unlined bed once it gets through the first year.

Carol, The other day I was looking through a pile of scrap lumber that Chris has left over from working on his house. Most of it wasn't anything I could use, but he had some nice lengths of treated wood posts. I told him I'm take them to use in the garden and he objected "But, Mom, those are treated posts". I had to explain that he was stuck in the past and that the various new ways they treat lumber nowadays are not worrisome like the old CCA-stuff. Because I always had been so adamantly opposed to using treated lumber in the 1980s, 1990s and earlier in the 2000s, he looked at me like I was from another planet or maybe like aliens had taken over my brain. He recently has started reading Mother Earth News but clearly wasn't up to speed yet on the new and safer treated wood products. It is hard to teach an old dog new tricks, but this is one area where I definitely have totally changed my mind, though only because treated wood now is safer.

One thing I'll never change my mind about is the use of railroad ties in an ornamental landscape or edible garden area. There are folks here (several different ones) who built their raised beds decades ago with railroad ties and who love them and who aren't worried about eating food raised in those beds. Now, the thought of eating food raised in beds surrounded by railroad ties just makes my skin crawl, and I don't think I'll ever, ever, ever change my feelings about that.

Dawn