pirl wrote: I voted "other": Trying to eradicate the evil Houttuynia cordata 'Chameleon'. Last summer through fall I spent 8 to 12 hour days digging it out of two fields where daylilies previously grew. Each daylily was potted up and will never be planted again for fear of spreading any errant pieces left in with the soil around the daylilies. We covered both fields with black plastic in November and December. Now it appears all Houttuynia is gone but it has wandered into two other gardens and the lawn, probably prior to the great black plastic experiment.
This photo, taken 11/7/11, shows just a small section of the problem area (before being covered with the black plastic to solarize the soil and kill the roots) as well as a portion of the lawn I had to dig out to get the portion that invaded the lawn in just this area but there is much more to it. Regardless of how deeply I dug it has returned in this area.
In the past I've tried dipping each leaf in straight (undiluted) Round Up and though it killed the above ground growth, it didn't have any effect on the roots. Undiluted Weed B Gon (why can't they spell these products correctly?) had some effect on the leaves but I'm not sure about the roots. My latest experiment is with undiluted Brush B Gon and, once again, the leaves look (mostly) dead but only time will tell if the roots are dead.