What fertilizer to put down at this time of year? We've lots of weeds

If no other Fertilizer was applied use Scotts Weed and Feed

I like to use weed and feed fertilizer in a hose end sprayer. No measuring, no mess. Hook it up to you garden hose and spray the lawn down. I prefer Spectracide Weed and Feed. Did it last Monday, killed the dandelions in three days. Now I got to cut the lawn today. Really grew out.

I agree weed and feed is really good.

Personally I do not agree with weed and feed. Best time to treat for weeds is in the fall but if you have a history of weed problems and need to treat in the spring, typical weed and feed combined solutions are designed to prevent weeds from seeding and seeds from sprouting. It does not kill existing weeds. There are herbicides designed specifically for treating broadleaf weeds, use these in spring if you have an existing problem and treat again in the fall. You can also try using herbicides designed for spot clearing as opposed to an entire lawn application.

If you have a LOT of weeds, just start over. Do you have a tiller? In the areas with the most weeds, till the area, let it sit for a week and till it again, do not rake it up; let the weeds die. How is your soil? You may need to till in some top soil and compost; then you can reseed it. Where do you live? Some grasses are better planted in the fall, and others in the spring. Or, maybe you want to eliminate the grass anyway and plant a nice ground cover.