Never plant this plant #1 - plume poppy

A colleague was conducting an informal survey about the worst plant we ever planted. Now that takes some thought. As a lawn tree the Phactor really dislikes sycamore, but none of them were my fault. Quite a few plants have been disappointments by not living up to the promisary pictures in catalogs. Although it has been, and still is, a huge pain, lily of the valley is lovely if only it had not been allowed to have taken over entire portions of our garden, a gift from the former laisez-faire owners. Oh, but then it was all clear. The absolutely worst plant ever deliberately planted was a plume poppy (Macleaya cordata). It's a big herbaceous perennial with rather striking leaves and in its first year it was amusing. In its second year it was surprisingly large, dominant even. But in the third year plantlets were popping up from roots over 10 feet from the crown of the plant. Plume poppy was clearly intent on taking over the world. Fortunately the roots were fairly shallow and it seemed it was growing faster than we could dig. The Phactor would recommend never ever planting this damned plant no matter how cool it looks. Staghorn sumac is less of a problem. Nominations are now open for worst plant you ever planted. Later your list will be compared to the rest of mine.