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"Creeping Charlie" (Glechoma hederacea) control

October 22, 2013

Ground Ivy, or “Creeping Charlie” is probably the most difficult perennial broadleaf weed to control in Iowa. It is an excellent indicator of compacted and poorly drained soils. Ground ivy reproduces by seed and also by rooting on its creeping stems. It was first introduced to the United States as a ground cover alternative in shaded areas. However, its extensive runners (up to 5-10 ft. long) not only began out-competing lawn grasses in the shade, but it quick spread rapidly into full sun.


Ground Ivy is easy to identify with its distinct square and prostrating stems, which readily root at the nodes (as seen to the right from the Scotts grass manual).  The leaves are round to kidney-shaped; borne on a short petiole.  When crushed or mowed the leaves give off an aromatic minty odor.  This aromatic odor often characterizes the Lamiaceae or “mint family” and contains many household cooking spices such as basil, rosemary, and peppermint. Ground Ivy has bright green leaves on an opposite leaf arrangement. The bluish-purple, trumpet-shaped flowers usually appear in May. 


The best time to treat ground ivy with postemergence herbicides is when it is translocating carbohydrates deep underground in the late fall and maybe even as late/after the first frost. The late fall application will not yield visible results until the spring. Repeated applications and persistence over multiple seasons may be required for complete control. Even with complete control there is a strong possibility it will move back in rapidly from a surrounding area. A combination of postemergence herbicides containing 2,4-D, dicamba, MCPP and triclopyr provides the best potential control. Below you will find a few additional pictures.


QUACKGRASS (Elymus repens) IN TURF

August 28, 2013

Here are some pictures of Quackgrass (Elymus repens).  This is one of most prevalent perennial grassy weeds in the Midwest.  It the hardest one to control in my experience.

The easiest way identify it is by its long clasping auricles wrapping around the stem from the collar. 

 It also has an extensive rhizome system below ground.  It is the rhizome that makes it so hard to control.  While systemics like glyphosate (Roundup) can translocate down and kill the rhizome, the rhizomes are often so extensive that the entire rhizome is not killed and the quackgrass comes back from the buds on the nodes of the rhizome.

Here is a recent picture from the turfgrass research area.  We noticed that quackgrass was spreading into a sandy area from the edge of a creeping bentgrass green.  This demonstrates the ability of this species to spread into surrounding areas.

In the final picture, Dan has pulled up a section of the rhizome to show how long they can get.  There are no effective selective controls labeled for quackgrass at this time.  We did have Certainty (sulfosulfuron) from Monsanto up to about a year ago, but that product has been removed from the market for use in cool-season grasses.

Non-selective control with Roundup is still the best bet and even that will  require persistence.  The best way to get rid of it in your lawn is to hit it repeatedly with roundup.  Then, till the soil and sod over the spot, rather than seed.  It tends to out compete seedlings, but has a hard time emerging through sod.