Weed & Feed. When it comes to putting fertilizer down, this is by far the most sold product for lawn fertilization at any hardware store or home center. But is it the BEST choice?
It sounds simple. I’ll go spread this all over my lawn and all the weeds will be gone, and I feed my grass at the same time. Not so fast. 
There are very specific ways and times that you can put down weed & feed and if you don’t do it correctly, all you are doing is wasting your time and money.
The “Weed” part of weed & feed ONLY works if the granular chemical comes in contact with the evil weed that you want dead. Then it must stay on the leaf of that weed for 24 to 48 hours. The only way that the granule sticks to the leaf is if it is wet or moist. That makes the best time to put this down as the first thing in the morning. Most of the time, there is dew on the grass in the morning so skip the coffee and get out in the yard and get the chemical spread. If you’d rather have some coffee and watch the morning news, now you have to put out the sprinkler and water down the lawn before spreading.
Now that you have the weed & feed spread, pray for no rain. No water can wash off the chemical for 24-48 hours, depending on the brand that you use. If it does, the weeds survive. Also, I will say that you don’t really want kids of pets in the yard during that time either because running around in the yard could knock the granule off the leaf and who wants their kids and pets in the yard when the granules have not been “watered in”. A couple other things about weed & feed. It only kills the weeds that are present and growing, right then. Second, the fertilizer you get is generally high nitrogen. Scotts weed & feed is 28-0-3. That first number is what make the grass grow, and with a 28 for the nitrogen, grow is what it will do. Get ready for every three-to-four-day mowing. Another “bonus” to having fast growth in fescue lawns is fungus. A new problem to fight in the hot days of summer.
So, what do I think that is better than weed & feed? If you’re lawn is overrun by weeds, I would recommend a good hose end liquid weed killer. There are several name brands. Ortho WeedClear (used to be weed-B-gone) or Spectracide Weed Stop but the main ingredient you are looking for is 2-4-D. That is what kills the weeds. They usually have other chemicals too like Dicamba which is the one that kills the clover (awfully hard to kill). If you have just a weed here and there, why throw all that chemical all over everywhere when it isn’t necessary. Buy a pump-up sprayer and mix the concentrated liquid version of the weed killer and spot spray. If you don’t want to mix and use the pump-up sprayer, there are ready to use products with built in sprayers you can use right away when you get home.
If your lawn still needs fertilization, then put your fertilizer down first (anytime during the day) then come back with the hose end weed killer spray. It’s a two-step process but you get your fertilizer watered in and for sure get chemical on the weed to kill it with a hose end application.
A couple other notes on applying any of the weed killers. Wait at least two to three days after your last mow so there is plenty of leaf material to catch the chemical. Second, if you have a bunch of the yellow dandelion blooms, do your self a favor and pick as many as you can before applying the chemical. Bees like dandelion blooms in the spring. If there is 2-4-D on the bloom and a bee lands on it, the 2-4-D will kill the bee as well as the dandelion.