Ask a Master Gardener: Autumn is best season for applying weed killer to lawnSend your gardening questions to firstname.lastname@example.org.
Q: How do I get rid of the weeds in my lawn? I have a lot of creeping charlie, some dandelions and a few other weeds that I don’t know the names of.
A: You have three choices. If the weeds are really bad, you can remove the existing lawn, either manually or by using glyphosate, which will kill everything. Then you can re-seed or sod.
If the weeds are bothersome but have not taken over your entire yard, you can spray (liquid works better than granular) with a weed killer containing 2,4-D and MCPP for creeping charlie or dandelions and triclopyr if you have violets. This is the best time of the year to do this as the plants are storing energy in their roots for winter and next spring and thus will draw the weed killer into their roots. Crabgrass and other annual weeds will die over the winter, but will come back from seeds next spring. They should be treated in the spring with pre-emergent controls. Make sure it is a calm day and no rain is forecast for 48 hours. Wind will blow the chemicals onto other plants and can kill them; rain will wash away the chemical before it has the chance to work. Creeping charlie likes to grow in shady spots, but if your lawn is sparse it will take over sunny areas, too. If your lawn is shady, replant that area with a type of grass that prefers shade. If it is weak, have the soil tested to see if it is missing any nutrients and fertilize accordingly.
The third option is to let it be and enjoy the beautiful spring flowers — the bees certainly do. In fact, creeping charlie, dandelions, violets and clover are important foods for them, and they can use all the help they can get right now. Instead of thinking, “I fought the lawn and the lawn won,” you can pat yourself on the back for having a bee-friendly lawn.
More info on this and other lawn issues can be found at our Web site: www1.extension.umn.edu/garden/.