I'd really appreciate some advise on this... can't decide what to do. Last week, I attempted to 'thin out' this so-called 'yarrow' plant which was taking over one of the raised beds next to the foundation of my house.

Then, holy yikes! Into the process, I realized this 'plant' (was really a monster) had this mucho extensive system of roots - just under the surface, it had competely consumed the entire 3' x 10' bed. There were mega long tap roots stacked up on each other (like coax cables, only fatter)...running down along my concrete foundation. Rather than just 'thin it out'...removed as much of the roots as I could, and think I got them all. Filled up 2 huge garbage bags with primarily roots, it took 2 days. Was planning to compost them once my pile got hot enough...

Since then, I've learned that it wasn't yarrow - its Tansy. (I think Common Tansy, not Ragwort) I was curious, because these roots were coming out of the ground clinging to (what looked like) rocks - but they weren't rocks, you could squish them in your fingers and the would turn to dust. Also, it seemed like the root ball of this plant was hoarding minerals for ages - when I finally got it out of the ground, it was sitting on a pile of what looked alot like very old clumps of rust. I thought it was weird. Since then, I've read that Tansy is unique, in that it can extract heavy metals out of conaminated earth. Hmmm...

While I have no reason to suspect that my house is sitting on contaminated earth, I'm feeling paranoid about composting these bags of roots. My current hot pile is right about 140 degrees, and getting ready to flip it - at which time, I could reasonably add the remains of the monster to the pile and FRY them. As I understand it, Tansy also sucks up 'good' minerals too... if that's true, I'd think it would make a good contribution to the pile. Right? I'm just worried about the possible presence of heavy metals... what's the worst case scenario. Could it wreck the whole compost pile, and if so... how would I know if it was bad? When my plants start to die - OR - when I get sick from eating stuff that was grown in this compost?

I hate taking stuff to the landfill, but some sites suggest thats what I should do with it, that it should not be composted. At this point... wondering if I should set up a seperate hot pile, just to compost the remains of the monster. If I did that, would there be any way to use the resulting compost 'with confidence' - short of having it tested? Even if I just used it on my inedibles (like Iris's)... if heavy metals were present, wouldn't I be adding them back to the soil all over again? I don't know enough about chemistry, except...can't some plants convert potentially toxic substances into more beneficial forms? Or, is that not the case for heavy metals...and I'm just confused.

What should I do...toss it in the pile as is? Or, is there a better way?

I thought about burning it too, but we are under fire restrictions...and no sign of rain in the near future.

Leslie - confused in Colorado

P.S. I think this is a link to pictures of the monster in question...

https://picasaweb.google.com/107677277907537328063/YarrowMonster