Field of Science

Showing posts with label invasive plants. Show all posts
Showing posts with label invasive plants. Show all posts

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.



Suppressed memories may be a good thing


This week heralded the beginning of the harvest of permanent prairie plots to get biomass data. Fortunately your memory of previous harvest seasons and how much work it entails dims, and you get newbie graduate students who know no better. Only 1/4th of a square meter is harvested but it can be a pretty impressive amount of vegetation in a community where the herbaceous vegetation reaches 2.5 meters in height and so dense it impedes your movement through it. While others were snipping TPP was marking out the portions to harvest and after just 1.5 hrs my hands and arms were covered in little scrapes, punctures, and abrasions such is the nature of prairie vegetation this time of year: hard, dry, sharp-ended and sharp-edged, like little hack saws. Unfortunately TPP's high mileage back was sore, so attention turned to sorting the bags of vegetation into piles back in the lab: grasses, forbs, various legumes, any exotic species, and a hemiparasitic plant. This is a really "fun" activity and much harder visually than you might imagine, but not so hard on the body. Harvesting is half done, and the sorting just barely started. Pile on the lower left is silky bush clover (Lespedeza cuneata), an invasive Asian legume. The 2nd image shows a thicket of this legume where it has all but replaced the prairie vegetation (except for the big grasses). It's so thick you have trouble walking through it, and it's essentially impossible to get rid of. Even if you nuked it with herbicide a sizable seed bank remains. Sad.