Control Parsley Piert in Grass
Parsley piert is a small weed which grows commonly throughout the UK but is often not noticed. Because of its small size, it becomes a problem mainly in turf where it survives low mowing heights. One of its main characteristics is that it tolerates a wide range of herbicides used selectively in turf, so it often only becomes noticeable when it remains alive and healthy in turf after other weeds have been removed by spraying.
Although it usually grows as a prostrate weed in turf, in a dense crop it can grow upright, growing 10-20 cm tall. It can cause problems in clover seed crops. It can also be found in pastures, especially newly sown ones, but also sometimes in established pastures where growth is not dense, eg if attacked by grub pests. It tends to grow as a winter annual, establishing in autumn, setting seed in spring or early summer then dying off.
Controlling Parsley Piert
A turf herbicide trial conducted in America a few years ago illustrated the tolerance of this species to herbicides very well. Young parsley piert plants were not affected by active ingredients such as MCPA, 2,4-D, MCPA/dicamba, 2,4-D/dicamba , mecoprop, triclopyr (Grazon) or clopyralid.
However it was controlled well by Axall (ioxynil + bromoxynil + mecoprop) (no longer approved on grass in the UK) and a mix of (picloram + triclopyr) (available as Loram + Woody/Grazon). Remember that new parsley piert plants establish wherever turf has been thinned out, especially in autumn. Therefore care is required when applying herbicides to ensure the turf does not get damaged removing one lot of parsley piert, as this could lead to further invasion by new seedlings. Both these herbicides can weaken fine turf if not applied carefully. We suggest a trial area wise to establish crop safety.
For more information on Loram and Woody click here