|Prostrate spurge, top and side views.|
Illustration: Common Weeds of the United States
Improve lawn care practices Prostrate spurge tends to appear where grass is thin and the soil is occasionally disturbed or subjected to prolonged dry periods. It is commonly found growing around the edges of a lawn next to curbs, driveways, and sidewalks, but it may be scattered through the grass as well. Improving lawn care practices to encourage thicker grass cover will help control this weed. This means fertilizing at least once or twice annually, watering to prevent moisture stress, and mowing regularly, allowing the clippings to remain so they can return nutrients to the soil.
Apply pre-emergence herbicide
Since it comes back from seed every year, you can also help prevent prostrate spurge by applying a pre-emergence herbicide in spring before the seeds germinate. Usually one application, followed by a light watering, in late April or early May will eliminate most annual weeds for that summer – provided the soil is not disturbed afterwards, and weather patterns are normal. If the weed has been a serious problem you may choose to make a second application, however, about sixty days after the first, for added protection.
Hand pull young weeds
If you find that pre-emergence control has not been totally effective and a few young plants have sprouted, just pull them out. They tend to have one long taproot, so gently gather up the top growth in your hand so as to not break it off, then pull straight up. As with any weed- pulling, results will be best when the soil is moist. Soak the soil first, or do your weed-pulling after a steady rain has soaked it for you.
Spray young plants with broad-leaf herbicide If there are too many young plants to pull by hand, you can spray them with a contact herbicide containing a combination of 2, 4-D and other ingredients such as MCPP, MCPA, or Dicamba. If the product contains Dicamba, be especially careful using it under young trees or shrubs because it can be absorbed through their roots when washed into the soil.
These broad-leaf herbicides will not harm established grass when used properly. They can, however, damage or kill broad-leaved (non-grassy) plants, including trees, shrubs, vines, flowers, fruits, and vegetables, if they are accidentally sprayed. They will also harm young grass that's not yet well-established.
When to spray
Spray when prostrate spurge is young and actively growing; these herbicides are not effective once the plants are older and have had a chance to toughen up. Choose a calm day when temperatures are not expected to rise beyond the low 80's and no rain is forecast for twenty- four or preferably, forty-eight hours. Rainfall within this time frame will lessen the herbicide's effectiveness considerably.
Control in gardens
In gardens, hand-pulling, shallow hoeing, and light mulching are usually sufficient to control prostrate spurge. Mulching denies most weed seeds the light and warmth they need to sprout, while any that do sprout through the mulch may be pulled out very easily.