A: The weeds present now are mostly a mix of broad-leafed weeds (clover, dandelions, etc.) and cool season grassy weeds like annual bluegrass.
The bluegrass would have been best controlled with your fall (September) application of Dimension pre-emergent. It’s too late to stop it now. The only treatment would be carefully applied shots of glyphosate like Killzall or Roundup, and those will kill your lawn as well if the turf isn’t completely dormant. Spot treat only the areas where you cannot tolerate the grassy weed at all for now and leave the rest alone. The good news: Annual bluegrass and annual ryegrasses will die once we get warmer in late Spring, quicker if you keep the lawn mown short. Get a jump on those next September and head them off next year.
Broadleafed weeds are easier to control. Apply ferti-lome Weed Free Zone when the nighttime temperatures for the next few days are expected to be over 40 degrees. Add one to three teaspoons of dish soap to each gallon of spray to act as a surfactant and apply from a pump sprayer.
And, to head off a similar problem before it occurs this spring – February applications of Dimension will prevent most of your spring-season crabgrass and dallisgrass issues!