TechNotes Tips - 04.26.01

Dandelions are flowering throughout the Midwestern United States. Once the yellow flower appears postemergent herbicide treatments are not far behind. Dandelions are a difficult weed to control. The besttime to spray for dandelions is when the “puffballs” are present. Before this point the weed is translocating most of its plant energy upwards for flower production and then later for “puffball” development. The puffball contains the seed. After the puffball phase, energy is translocated down for vegetative growth. This downward movement enhances the activity of herbicides applied at this time. Given that many customers do not want to wait that long, try to apply postemergent herbicides when soil temperatures are warm (~ 55F). Warm temperatures promote dandelion growth and thus uptake of the herbicide. Multiple applications are needed to control this weed. Culturally, maintaining a dense turf will reduce dandelion populations over time.

Finding grubs this time of year in home gardens and when edging ornamental beds may cause alarm with your customers, but these grubs are causing no harm (they are not feeding). The grubs will eventually move down into the soil and pupate.