Source(s): Jacob G Price


Chamberbitter is a summer annual weed that is commonly found in turfgrass and ornamentals that emerges in great numbers in July. It is native to Asia but found throughout Georgia, Florida, Alabama, and Texas. It is in the spurge family and reproduces by numerous seeds which are found in the fruit attached to the underside of the branch.



Chamberbitter is a small erect plant with angled or grooved stems. The leaves are thin and have smooth margins. Leaves are also oblong and arranged in alternating rows of two on the branch. It is easily identified by the small round fruit on the undersides of the stems.

Control: Turfgrass

For centipedegrass and St. Augustinegrass, Gallery and Atrazine are labeled as a preemergence control. Apply between April and May. For postemergence control use Atrazine at recommended rates on St. Augustinegrass and Centipedegrass. Apply two applications spread three weeks apart. As an alternative, “Prompt’ (BASF, contains atrazine + bentazon),may be used at recommended rates. Again, two applications spread three weeks apart.

Control: Ornamentals

Preemergence options are Ronstar 2G, Snapshot, Factor, and Gallery. Apply in March and re-apply 2-3 months later. This is a difficult weed to control in ornamentals, therefore two applications of one or more of the above products will be necessary. Pre-emergence herbicides will not be totally effective. There are no postemergence over-the-top controls in ornamentals. Direct applications of Roundup Pro or Finale (without contact of ornamental foliage) along with supplemental hand-weeding will control this weed. Additionally, research has shown that chamberbitter seeds require light in order to germinate. An adequate layer of mulch will block sunlight and help to limit the presence of this weed in ornamentals.


Center Publication Number: 67

Jacob Price
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