I would not use tar paper to line planters used for edible crops. Both tar paper and your pressure treated lumber have toxic ingredients.

Hi rhizo_1,

What is your information source for tar paper leaching toxic materials? If that were the case, wouldn't we have stopped using it on roofs along time ago?

The tar in tar paper contains creosote, the same stuff used on rail road ties and telephone poles as a wood preservative.

Some nations have banned it's use due to their believing it to be carcinogenic.

On a past property I had railroad ties that were fairly fresh and nothing, including grass and weeds would grow within a few inches of them. I currently have some older ones (less cresote to leech) and grass actually grows in them.

Nevertheless I don't think tar paper would be something I would want lining a container

Blueberry, I consider it common knowledge that tar-paper and other creosote and cresol containing materials are toxic. I don't have a list of resources for you, but I'll do a quickie search and post a good link.

Yes, the water run-off from a roof can contain hazardous chemicals. I'd use that water only for ornamental plants. Contaminate laden water is one way that these chemicals can enter the body...by drinking it or simply touching it.

You'd be exposing yourself to the chemicals in cresols (like methyl phenols) and creosote on a chronic basis by using it to line your veggie containers. Did you know that creosote is a well-known carcinogen?

Check out the attached link. I've only skimmed it, but it appears to be factual and thorough. I also did a search using 'tar paper toxicity' as my search words, which resulted in quite a bit of helpful information.

More that we all want to know, probably, lol!

Here is a link that might be useful: C'mon, let's read this together!

Thanks. I can use 6mil plastic instead of tar paper...do you think it will prolong the life of the planters significantly (provided it doesn't get punctured)?

Here are some plans for a wooden planter. It has a plastic liner and all the details of how they attached it. Might give you some ideas.

Thanks Rhizo for the informative article link. Guess I better stay away from the tar paper. Maybe I should just resign myself to the fact that the boxes will probably fall apart in 3-5 years and I'll have to build new ones when they do. Maybe that'll be a subtle reminder to mix up new container soil.

I know this is an old post..but I've had whisky barrels hold up for 25 yrs. They used to be 12 bux a half. Although those days seem to be gone, you can still get longevity and they are awesome for growing plants in.