Common bad guys

Common purslane (Portulaca oleracea) can produce 240,000 seeds per plant and the seeds can stay viable for up to 40 years. It mostly grows at the edges of the lawn, in sidewalk cracks, next to a driveway. One way to contain it is to alter your watering patterns so bare soil is not watered. Seeds can continue to ripen after the plants have been pulled. Any part of the plant can resprout. The seeds sprout when the soil temperature is near 70 degrees and the air temperature 70-80 degrees. Three inches of mulch will prevent the seeds from germinating. Pre-emergent chemicals are effective if applied before the seeds sprout.