Creeping Charlie in Turf
The following question was sent to the P&PDL diagnosticians here at Purdue University:
Question: We have a pronounced problem with Creeping Charlie and are about to try a Borax application. Is this worthwhile or is there something better?
Answer: Creeping Charlie is a difficult weed to control because it spreads aggressively by stolons and rhizomes. Plus herbicides often will not translocate through these plants parts and this weed will regrow from the rhizomes and stolons. Don't bother with Borax, it can damage your turf plus it is not labelled for turf use which makes it illegal.
Establishing and/or improving a grass stand to outcompete Creeping Charlie is essential, this is easier said than done primarily because Creeping Charlie thrives in the shade and turfgrasses have a tough time in the shade. For most effective control a multi-pronged approach is needed including:
Mowing the established turf at 3" or more
Broadleaf herbicide application in the spring after flowering and then again 3-4 weeks later. You could and probably should also apply in the fall (Sep 15-Oct15) and again 3-4 weeks later. Unfortunately, these applications may be needed for many years to be most successful.
Fall fertilization to thicken the grass stand.
Regular overseeding in the fall to thicken the stand even more.
Controlling Creeping Charlie takes a lot of work and may not be totally successful. Thus many homeowners learn to accept Creeping Charlie and give up on controlling it.
-Zac Reicher, Turfgrass Extension Specialist (7/31/98)