Where NOT to Plant ~Gardening for Health~
I want to think that most people garden for health benefits, but I see all these so-called "helpful" homestead hacks that make me shake my head. Many folks assume these garden hacks are safe for growing food in, and they are not. If you are planting for your health, please consider the following.
Planting in Tires
According to the EPA, benzene, mercury, styrene-butadiene, polycyclic aromatic hydrocarbons, and arsenic, among several other chemicals, heavy metals, and carcinogens, have been found in tires. (1) When the material gets hot, it can increase volatile organic compounds or VOCs and can leach into the air and soil as the tire biodegrades. (2) The EPA found tire mulch and recycled tire pavers hazardous to use on children's playgrounds due to off-gassing alone. Watering plants inside these tires help them heat up and get steamy in summer, speeding up the biodegradation. They are so bad for the environment when you get new tires on your vehicle, you get charged extra to have your tires properly disposed of, and it's about the most toxic thing you can plant in. It's a giant ring of decomposing toxic chemicals. There is a reason we aren't making cereal bowls out of used tires.
Harvesting rainwater off the roof of a structure to water garden produce or animals isn't as clean as it sounds. (3) In Washington, the Department of Ecology investigated the toxic chemicals found in roof run-off. They found that total arsenic, copper, lead, and zinc concentrations were consistently measured in run-off from all new roofing materials evaluated. As petrol chemicals (TAR!) in shingles, paint, and metal in roof sheeting, and CCA treated cedar shingles degrade over the roof's life, they will release more chemicals. There is a reason camping gear and travel water bottles are now stainless steel and not galvanized tin. Stainless steel is a safe, clean, and healthy surface to hold potable water. If you are using a catch-tainment system a filter is necessary. I still have to use a plastic tank to hold water for my garden, but we use filtered pond water, and the water only sits in the tank for a day or two at a time.
Planting Next to the House
Most people harvest rainwater from the roof because they garden next to the house, which is another extremely toxic area to plant. (4) When homes are built, the dirt around the foundation is exposed to multiple environmental toxins such as metals from nails, caulking, and sawdust from contractors cutting treated siding and trim. As treated wood siding and paint degrade, it ends up in the soil next to the house. Often older houses need to have loose paint scraped before painting, these homes may have had lead or arsenic-based paint scraped off and onto the soil, before regulations were made for proper cleanup and handling of the toxic substances.
Treaded wood from decks and sidings also leach incredibly toxic chemicals into the soil. Chromated copper arsenate (arsenic) (CCA) is a pesticide/preservative used to prevent rotting in lumber designed for outdoor use. CCA contains arsenic, chromium, and copper. CCA-treated wood is used virtually anywhere outdoor lumber is on a home, including sill plates, decks, and picnic tables. CCA (pressure treated) treated wood can be hazardous to human health because arsenic is a known carcinogen. Raised beds made from treated lumber will leach these chemicals into the raised bed, even through fabric liners. (5) Public Health and Social Services advise against the use of treated wood for raised bed gardening.
Foundations around homes are heavily treated with pesticides. (6) Diazinon is a pesticide that was widely is used in the United States until 2004. (7) Diazinon adversely affects the nervous system but is still used on 40 crops in non-organic agriculture. Home Defense (8) anti-pest products contain the chemical Bifenthrin, listed as a "possible human carcinogen." Termite treatments are also placed around the foundation of a home that also contains toxic chemicals. These chemicals kill bugs because they are small. People take longer to show the effects because the toxic load takes longer to absorb enough to show symptoms, but it adds up over the years.
Some homes have toxic waterproofing plasticizers put on foundation walls to keep basements dry. These tar-like chemical products aren't designed for agricultural use, so they aren't made to be used near where food is grown.
Planting in Straw Bales or Hay
Straw seems like an all-natural substance. Is it just grass, right? Well, it used to be years ago before agricultural chemicals were developed for weed-free planting and speeding up the harvest. Now there are preservatives in the hay and straw. (9) Commercial hays and straw available at large box stores are treated with preservatives so the hay and straw can stay on the store shelf without molding or growing fungus. If the straw comes from a field that was sprayed in the last few years with a herbicide containing the chemicals aminopyralid, clopyralid, picloram, aminocyclopyrachlor, or glyphosate, it can harm your garden plants. Straw comes from oats, wheat, barley, buckwheat, and rye plants that often are treated with these antifungal chemicals in the field. Plants affected by these chemicals in bales of hay or straw get leaves that curl and look blistered, and the tops often die off when the flowers are starting to set.
A study in the Netherlands (10) found up to 13 types of mycotoxins in hay and up to 10 different pesticides and fungicides. Mycotoxins are naturally occurring toxins produced by certain molds (fungi) found in food that are harmful to humans in large doses.