Universal poisons like poison ivy should never be included in compost. Other plants causing skin irritation include cow parsnip, dog fennel, nettle, and poison sumac.
There is a lot of hands-on work when composting. Materials are gathered, put in a compost pile or bin, turned several times, harvested, and spread. Avoid materials that would be detrimental to handle.
Poisonous to Everyone. Neither poison ivy nor poison oak should be included in any home composting system. Touching them causes a strong reaction in most people, so I would classify them both as universal poisons. Universal poisons should never be included in compost. Other plants causing skin irritation include cow parsnip, dog fennel, nettle, and poison sumac.
Allergies, Strong Reactions. Some plants may only be poisonous to a limited number of people. Always consider these individual sensitivities. I grow strawberries, but I have a friend who is allergic to them. If he touches a strawberry, he reacts so strongly that he becomes bed-ridden for a week. If he accidentally eats one, the impact is so severe that he we must take him to the emergency room immediately.
Though I would readily throw wastes from my strawberry patch in my own compost, I would not include them in his pile. Even if he wasn’t the composter in the household, I would not compost them on his property. The consequences are too high to risk that he would be exposed to “dust” of decomposing strawberries when the pile is turned or that the finished compost would be used on a tomato plant from which he might pick and eat an unwashed tomato. It makes no sense to take a chance of exposure when allergies are this severe.
The compost in my tumbler can be turned without my touching the compost so I don’t risk getting skewered by thorns.
Mild or Inconsequential Reaction. Holly that grows near my home has leaves that are extremely pointed and covered with a substance that burns badly. When I handle them, they prick and sting my hands and arms. I’ve never considered them dangerous, just extremely unpleasant. So if I find these leaves in the bags I have collected, I always put them in one of my enclosed compost tumblers while wearing gloves. There they can be turned and composted without my having to touch them.
The prickly surface of comfrey causes me an even milder irritation. I choose to shred and deposit it in my pile while wearing gloves. Comfrey composts so fast that I usually have no issues with it once it is in the pile.
Both of these plants cause a mild skin reaction of redness and burning or itching. I could avoid them totally and not risk this irritation, but I’ve decided that I’ll take these precautions and put up with reactions from accidental exposure. This is not a decision I would make for someone else. I am the only person affected by what goes into my compost, and I’ve decided I’m willing to take this risk.
Potential Injury. I have rose bushes, as do my neighbors, and the thorns on some species become very large. If I have time, I wear gloves and snap the thorns off before putting the stems in my pile. If I don’t have time to de-thorn rose stems, I put them in my compost tumbler so I don’t risk getting skewered by the thorns. The compost in my tumbler can be turned without my touching the compost so I don’t risk getting skewered by the thorns.
Then I make sure that particular batch of compost is applied to the lawn and not applied near any rose bushes in the garden. Some rose-specific pathogens may not be killed by home composting. Re-applying rose-waste compost to rose bushes might increase the chance of passing on rose-specific disease. To be safe, I apply it to the lawn instead.
Mary Tynes, Master Composter, www.mastercomposter.com
Image Credit (top left): http://www.flickr.com/photos/cygnus921/2620415235/
Image (bottom right): Spinning Horizontal Compost Tumbler
