31. Still, witchweed has demonstrated a wide tolerance for soil types if soil temperatures are favorably high. 32. A rough approximation of the initial soil temperature is the average daily temperature for the region. 33. Workers may only forage for several minutes when soil temperature is well above their thermal maxima. 34. A 2-to 3-inch layer of mulch will conserve soil moisture, moderate soil temperatures and discourage weeds. 35. It also conserves moisture and maintains soil temperature conducive to the growth of soil building micro-organisms. 36. Ideal soil temperature for germination is 60-65 degrees. 37. They prefer soil temperatures of at least 75 degrees and are very sensitive to ultraviolet light. 38. The nymphs emerge on a spring evening when the soil temperature at about depth is above. 39. "Don't be in too big of a hurry until the soil temperature gets around 63 degrees. 40. The color of the ground cover and its insulating properties have a strong influence on soil temperature .
