• Snag Island Community Garden posted an update 1 month ago

    Hey everyone.
    This is going to sound like a silly question but I am going to ask away anyway!!
    Tyre’s for growing potatoes. Now I know over the years there has been much said about this because of the toxins found in tyre’s. However I came across a site that sells tyre-mulch in Australia and this is what they say about toxins. It is a long read but would love to know everyone’s thoughts about using tyre’s for a potato bed!!
    Is Enduro Rubber Mulch Toxic?
    No. A carrier solvent more efficient than water would be needed to extract toxic chemicals from tyre shreds in quantity; and a suitable non-polar vehicle would be required to penetrate protective skin layers for significant absorption. This was deemed implausible in a playground situation.
    Toxicity rubber mulch is considered non toxic. Based on toxicity characteristic leaching procedure conducted on recycled tyre shreds, the following trace metal elements were determined to be significantly lower than regulatory threshold limits: arsenic, cadmium, chromium, lead, selenium, and silver. Source: criteria of selecting toxicity characteristic leaching procedure and synthetic precipitation leaching procedure tests to characterise special wastes. (Dr Chinshin Sheigh, Florida institute of technology) oral ingestion is deemed to be low in over all hazard because ingestion of tyre shreds on the ground is not likely, and the gastrointestinal tract is unlikely to be efficient in extracting toxic chemicals from the tyre shred. Tyre shred does not contain chemicals with high vapour pressures, thus, exposure via inhalation is deemed inconsequential and resulting hazard negligible. Dermal exposure is deemed to be unlikely and therefore to present low overall hazard.
    Leaching a number of studies have been done to determine the potential for leaching from recycled tyre shreds. Increased levels of zinc and iron were found in soil tilled with raw rubber shred particles (5ml and less) when tested annually for 4 years. The amounts detected were below levels of concern and posed no hazards to water quality. No toxicity to turf grass or athletic fields were detected. Zinc that had leached from tyre shreds was determined not to pose any potential harm to the environment.
    What if rubber mulch is swallowed in 1994 Maryland environmental services (MES) put this question to a series of tests. A 2cm piece of mulch was added to hydrochloric acid (stomach acid) and appeared to indicate only fibrous reinforcing strands were dissolved. The rubber did not appear to be affected in any way. What does this mean? If a piece of rubber is swallowed, it should not cause any acute or chronic problems. Short term issues, such as an upset stomach will be a function of the amount of rubber swallowed. As to the fate of the rubber swallowed, they are eventually evacuated from the body, just like any other non-digestive material.
    http://www.rubbermulchaustralia.com.au/PDF/Current%20Garden.pdf

    • Hi @snagisland have sent the word out for a response.

      Here are a couple of other options from Green Harvest and Diggers Seeds…
      ——————-
      GREEN HARVEST POTATO PLANTER BAG
      These large professional quality planter bags are ideal as a productive alternative for raising potatoes. Planting instructions: 1/3 fill the bag with good quality potting mix, compost etc. Put 3 – 5 spuds on the surface then cover with a few centimetres more of mix. When shoots emerge, add mix to cover; continue to ‘hill up’ as shoots re-emerge until foliage is above the top of the bag.

      By this method you can increase your yields hugely as potatoes will produce along the entire buried stem (at least 400 mm, a depth many Australian soils will not achieve) Potatoes are ready for harvesting when the majority of the tops have withered; this can be from 12 to 20 weeks after planting, depending on the variety. Diameter is 460 mm and height is 460 mm – 75 litre capacity.

      $12.95

      https://greenharvest.com.au/tools/pots_and_planter_bags_prod.html#PotatoPlanterBags
      ——————-
      DIGGERS SEEDS HAVE A POTATO PLANTING TWIN PACK – which is out of stock at the moment…
      Want to grow potatoes but don’t have the room? then grow them in this planting bag. made from UV protected woven materials and has a resealable window for easy harvest. Ideal for patios, balcony and any outdoor space. 40CM DIAMETER 55CM HIGH with resealable window for easy harvest.

      $16.50

      https://www.diggers.com.au/shop/vegetables/potatoes-and-other-tubers/potato-planting-bag-twin-pack/hppbs/
      —————–

      Cheers

      …Fiona
      ACFCGN website volunteer support