Dear Bouncingbet-in-the-garden,

 Bouncing bet (aka soapwort and other common names) was introduced from Europe as a garden plant and has now escaped and become established as a weed in the region. It is poisonous but rarely grazed.  Saponins (soap-like compounds) are the primary toxins present in Saponaria especially in the seeds. If eaten in sufficient quantity, the saponins may cause acute hepatopathy and death. The seeds which are especially toxic may contaminate cereal crops.

 It spreads rapidly and replaces plants of greater value, but you may know of this.  An alternative to planting bouncing bet is Garden Phlox (Phloxpaniculata).

 As a weed, bouncingbet or soarpwort is on the Colorado noxious week list B and is required to be either eradicated, contained, or suppressed depending on the local level of infestation.

 https://www.colorado.gov/pacific/agconservation/bouncingbet

 As noted in the fact sheet from the above bouncingbet page:  the key to controlling Bouncingbet is to eliminate seed production while depleting the nutrient reserves in the roots. Restriction of soil water may help, but may be difficult in your situation. Continued removal of blooms and pulling/digging may be your best approach, depending on the size of the area.

 Selected herbicides are listed at the tail end of the above fact sheet.

 Additional bouncingbet herbicide control options may be found from other extension websites, for example

 wric.ucdavis.edu/information/natural areas/wr_S/Saponaria.pdf

 and

 https://www.ag.ndsu.edu/weeds/weed-control-guides/USDA-Final.PDF

 Both of these sites suggest fair control obtained using glyphosate. Please follow the mixing and application instructions provided with the herbicide for control of bouncingbet. Some of the ready-to-use (RTU) products may be of the incorrect strength for this weed, so please investigate this aspect through the manufacturer of the herbicide.

 If you have little success with either approach, please report back.

 Best regards,

Frank

CMG Bounder County