| Last fall I constructed a cold-frame out of pressure-treated lumber. After the fact I found out that this wood shouldn't be used to grow vegetables in. Is there any way in which this cold-frame can be modified to be used for vegetables? |
| There is conflicting evidence about whether pressure-treated lumber is acceptable for use around food crops. Some research results say its fine, that it doesn't leach toxic chemicals; other results say that it does and should not be used around food crops. As far as sealing your existing wood, I've heard of several different methods. I don't know if anyone has studied the effectiveness of them, however. Perhaps a combination would be most effective. You can paint the wood with several coats of an appropriate sealer. You can line the structure with heavy plastic sheeting. You can construct a "foundation" using masonry, that would lift the cold frame so it isn't in contact with the soil. You can cover horizontal surfaces to eliminate water absorption. Here are a few web sites with information about pressure treated wood. The following is a message board about using pressure treated wood in gardens. I cannot vouch for the accuracy of any of the statements, but it does provide some interesting options and opinions: http://www.gardenweb.com/forum... Organic Gardening magazine has been involved in the discussion of pressure-treated wood: "How can I preserve lumber without toxic chemicals? http://www.organicgardening.co... I do not know if this offer still stands, but Organic Gardening magazine used to offer copies of an article they published in 4/97 on the subject of pressure-treated wood, including their updated bibliography of scientific studies. Their address is: Organic Gardening, 33 E. Minor St., Emmaus, PA 18098. I believe they requested $2.00 for postage. Other sites: The American Wood Preservers Institute http://www.awpi.org/ The U.S. Environmental Protection Agency http://www.epa.gov/opp00001/ci... http://www.epa.gov/gbwebdev/ge... http://www.epa.gov/gbwebdev/ge... Hope this helps. |
