Life can be a bit easier if you learn from the mistakes of others. On a few occasions TPP has issued you plant warnings; fail to heed them at your own risk: plume poppy, giant lamb's quarters, Houttoynia cordata, spreading hardy bamboo. Never wrote the blog about the Houttoynia or the bamboo; the Houttoynia may be the worst, spreading like wild fire and while the flowers are cool and the leaves attractive, it will come back from the tiniest bit of rhizome, and it's brittle, so you are sure to break it into lots of pieces (think Mickey Mouse as the sorcerer's apprentice and brooms).
Now every garden has some tough spots where gardeners keep looking for something tough to fill a spot. One of ours is a smallish triangle, 3-4 foot on a side, pond margin on one side, base of a rock garden on the other and a looming tulip magnolia on the hypotenuse. So that resulted in trying a fringed yellow loosestrife (Lysimachia ciliata); it seemed able to deal with the shade and wetness, and its sort of native and rather handsome, especially this purple-leafed cultivar. But previous experience with L. vulgaris had not really taught us a lasting lesson. And to make us sound really foolish, it takes an effort to control L. clethroides, the very handsome gooseneck loosestrife, inherited with the house purchase.
Those are our slow-learner credentials, but last year TPP put in 3 one gallon plants, as an experiment, and this year the yellow loosestrife came up every where. If you live in the upper midwest and you see this nice purple foliage sprouting with the prominent ciliated margins on the petioles, then TPP is truly sorry, it got away. As you can see from the images it produces a network of rhizomes some as long as 2 feet sending up new shoots along the way. It took an hour and a half with a spading fork, along with brute force, to remove the 3 plants. The plant material nearly filled a 30 gallon trash container. Don't plant this plant! Don't plant loosestrifes, period.
What if we done the Schrodinger's cat experiment?
8 hours ago in Doc Madhattan