Artillery Weed (Pilea microphylla) Control in Ornamentals

If you have grown in a shadehouse or greenhouse in central or south Florida, I am sure that at some point you have probably had to deal with artillery weed.  This weed is most commonly seen in moist areas usually in the greenhouse or shade house.  Commonly found in propagation houses.  It is a creeping plant and re-seeds itself with vigor and can quickly become a problem.

Dr. Chris Marble has done some work looking at controlling this weed with pre and post herbicides in ornamental crops.  Here are some pictures of the work that he shared with us at the Woody Ornamental Production Field Day at Balm and will be published in this year's Proceedings of the Florida State Horticulture Society.
Here are the results of the post-emergent herbicide treatments 5 weeks after treatment (WAT).  You may need to click on the pictures in case they aren't displaying correctly.

Although you can't really tell from this picture in a few more weeks the best treatments were Ronstar, SureGuard and Finale.  Roundup generally sets the plant back with yellowing and a slow down of growth is achieved, however, it is usually a short-term setback and the plant resumes growth after a while.

Here are the results of the pre-emergent treatments 8WAT