Prostrate Spurge, also known as spotted spurge or creeping spurge (Chamaesyce maculata and Euphorbia supina), is a low growing, mat-forming, summer annual.
A common weed in newly established lawns or thin lawns, it thrives on harsh, sun-baked sites. I have observed spurge growing in hard compacted soils as well as cracks in sidewalks and asphalt parking lots.
The leaves have a red blotch in the center and reddish stems that ooze a milky sap when broken. It's a vigorous plant
that can grow up to three feet in diameter.
|Illustration courtesy of USDA-NRCS PLANTS Database / USDA NRCS. Wetland flora: Field office illustrated guide to plant species.|
Improved lawn care practices, most commonly proper watering, mowing and fertilizing, will ensure your grass is healthy and vigorous while keeping spurge in check. It often appears in bare areas, dry spots, thin grass stands, and along the edges of sidewalks, curbs and driveways.
Hand weed when the soil is moist. Its an easy weed to pull. Pulling from the center of the plant helps extract the taproot. Removing plants when they are young and before they produce seeds will keep spurge populations down. A single plant is capable of producing thousands of seeds throughout the growing season.
Pre-emergent herbicides can be used to keep seeds from germinating in the spring. Prostrate spurge seeds germinate when soil temperatures reach 60° F - generally by the end of April. One application will usually do the trick. Thin lawns or unusually wet weather might require a second application - spaced 60 days apart.
Broadleaf herbicides are most effective on spurge when the plants are young. Mature plants are can be resistant to post-emergent herbicides. A product containing 2,4-D and other ingredients such as MCPP, MCPA, or Dicamba is recommended.
Vinegar-based (20% acetic acid) or Citric Acid herbicides - considered
natural organic weed killers - can be used effectively in landscape
beds, sidewalks and driveways. Spray them when they are young for best
results. These herbicides are not selective - they will damage any
foliage they come into contact with.
Leaves are pale green, opposite along the stem, oval, and small - up to 3/5 inch long. Leaves form a purple blotch in the middle.
The prostrate stems form a dense mat that smothers desirable grass plants. Stems are green to red, branch freely and emit a poisonous milky sap when broken.
Flowers are very small and inconspicuous, they are borne on the leaf axils. Spurge starts to flowers about three weeks after germinating.
Purslane and spurge are often found growing together. Purslane flowers are yellow and it has fleshy stems and leaves.
Prostrate knotweed also forms a dense mat. However, knotweed has bluish-green leaves and does not emit a milky sap.