You may need gloves and an overcoat when venturing outdoors, but winter weeds are thriving in the cold. Their bright green tufts glow brightly in dull, brown front yards.
If this describes your lawn, you probably did not apply corn gluten meal in the fall, before winter weed seeds germinated. In January, while summer lawn grasses are dormant, kill winter lawn weeds with a vinegar herbicide applied with a spray bottle.
Spraying vinegar herbicide on dormant grass won’t harm turf, but if your lawn is an actively growing cool-season grass the herbicide will kill it along with the weeds. You can make a vinegar herbicide using the recipe below, or you can buy a ready-to-use formula at a garden center that sells organic products.
A couple of other cool-season weed problems also can be addressed now.
- If winter weeds are growing through gravel mulch and in cracks and joints in concrete and other paving, kill them with a vinegar herbicide. Vinegar herbicides work when you spray them on actively growing plants. These herbicides are not selective, so be careful where you spray. Avoid plants that you don’t want to kill.
- Weeds growing in planting beds are taking advantage of a gardener's inattention. These unwelcome visitors can be killed during winter by cutting them off at ground level and covering the stumps and the surrounding area with half an inch of compost topped with five layers of newspaper or one layer of corrugated cardboard. Use a water hose to saturate everything, and then top the newspaper or cardboard with 2 to 4 inches of shredded mulch. Leave everything in place until spring to kill the weeds' roots. If a few weeds manage to grow through the barrier, you can kill them by spot-spraying with a vinegar herbicide.