Ask Mr. Smarty Plants

The key word here is "winter."  We're assuming that what you have are winter annuals that should be dying a natural death soon. However, and this is a big "however," they will take steps to perpetuate themselves before they go. All plants exist to reproduce, and the blooms and seeds near the end of their life cycle are the keys to that reproduction. You should get those weeds out before they have a chance to seed. Mowing them very low is one way, pulling them out is another. "Weed and feed" fertilizers are targeted toward one kind of weed, the broad-leaf or dicot. The problem there is that many of the plants you are referring to as weeds are also grasses, or monocots, just as your lawn grass is. You will just be feeding those grasses/weeds that you don't want. The Lady Bird Johnson Wildflower Center recommends neither for nor against herbicides, but we urge that if they are used, it be done so responsibly. Overuse can result in runoff into the water supply when it rains or with irrigation of the lawn. It's also important to remember that most of your ornamental plants, including trees, are dicots and can be adversely affected by coming into contact with the herbicide in your fertilizer.

So, we recommend that you take steps to prevent your weeds from reproducing. And, when Spring comes and the lawn greens up, along with the grassy weeds (which are probably natives and actually belong here), just mow it, it's green.