Never plant this #2: yellow loosestrife

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.

Slow learners

Some people are just slow learners, or stubborn. In this case some people must learn the hard way about planting certain plants.  TPP has warned you about plume poppies (here also) and bishop's weed, and a hardy bamboo; never plant these plants, period.   In the not quite so terrible category, but you are properly warned anyways, are loosestrifes (Lysimachia).  Presently one shady bed has a sizeable population of L. clethroides, the gooseneck loosestrife. In flower the curving racemes of white flowers are quite handsome, but it takes some effort to keep this population in its place. If would be harder if the area were wetter.  The worst species in our experience is L. punctata, which can really crank out the rhizomes and aggressively colonize an area although the dense spikes of yellow flowers are very handsome, and like the others, it flowers in summer when flowering of other plants is limited. Fortunately, L. congestifolia is not hardy here and must be replanted, but it's a low spreader just like L. nummularia which can even invade lawns. So why or why did the Phactors decide to try yet one more species, L. ciliata, in a semi-shady area near our

pond?  Well, it's flowers are large and pretty of course (image courtesy of Wouter Hagens, Wikimedia Creative Commons), and this is a bit of a tough place, but something tells TPP this decision will be regretted. Even as the plants were slipped out of their 4" pots, the rhizomes were ready to go suggesting this is another spreader, although this location won't let it roam too far circumscribed by barriers as it is. Anyone with experience with this species can let us know how big of a mistake we are making, but we'll probably have to learn for ourselves.  In the questionable plant ethics category, our local gardening shop (who called it to TPP's attention) has a variegated variety of creeping Charlie for sale as if anyone would deliberately pay money to plant it!  It was part of a whole shipment, so not deliberately selected.