P&PDL Picture of the Week for
October 25, 2004

Controlling Wild Onion or Wild Garlic in Lawn

Zac Reicher, Extension Turfgrass Specialist, Department of Agronomy, Purdue University

Wild onion and wild garlic emerging in the southern two-thirds of Indiana and these are difficult-to-control weeds. These weeds look very similar to the garden variety onion except the stems of the wild type are much thinner and do not grow as tall as the garden variety. The most effective method for controlling onion and garlic is to create a dense turf through proper fertilization and regular mowing, thereby making these weeds less noticeable and less problematic. Wild onion and garlic die back to underground bulbs during early summer, but bulbs will germinate during the fall and winter.  Selective chemical control is difficult and normally ineffective, so co-existing with these plants is often the best choice. One method is to apply 2,4-D immediately after mowing so the herbicide can enter through the cut leaves. This will usually burn back the leaves but may not kill the underground bulb, thus multiple years of applications will be needed.

Controlling broadleaf weeds after the drought

Zac Reicher, Extension Turfgrass Specialist, Department of Agronomy, Purdue University

Now that the lawn and weeds have greened-up from the recent rains, broadleaf herbicides should be effective yet this fall.  Though these herbicides work faster when the plants are actively growing, these herbicides will still work as long as the plants are green and photosynthesizing. Therefore, applications into November will work, albeit slower. You may not even see any effect this year, but weeds will die over the winter.  However, herbicides that contain carfentrazone (FMC’s Quicksilver, PBI Gordons’ Powerzone and Speedzone) will still give a response in 7 to 10 days even when applied in late October or early November. To maximize success with any broadleaf herbicide, try to apply on a dry, warm (>550F), sunny day to maximize effect. If you have problems with winter annual broadleaf weeds such as common chickweed, it makes more sense to apply a broadleaf herbicide as late as possible in the fall to control most of these late-germinating weeds. This would be especially important on fall seedings that may be struggling because of weed cover right now. More information on late fall broadleaf weed control can be found in Turf Tips from Aug. 9, 2004.


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Wild garlic

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service