I was actually going to water in some fertilizer after this next cold front and noticed on the bag it said do not water in. I was under the asumption you always watered in fertilizer as long as you dont overwater and wash it all away.

Depends on the fertilizer and what you are fertilizing..... I'm going to assume its grass (based on the thread title). Is it a synthetic granular fertilizer? If so, I believe those have to be (or at least should be) watered-in to work properly. I know some organic fertilizers do not require watering-in.

Also, this may be a marketing ploy and they may have found that customers think a product is easier to use if it doesn't require watering-in or that when customers do water it in they tend to over water (washing the fertilizer away) and then come away with the opinion the product does not work.

Water it in so if we get a big rain it won't all wash away.

Very true - any fertilizer that sits on top and doesn't come as a spray, needs to be dissolved to get into the dirt. It doesn't do any good if it just sits on top of the dirst...and your sidewalk. As crimson says, be sure to get it watered in (at least once) before it rains or the rain will simply wash 75% of it away. That first wattering can make a world of difference. It may not all dissapear from the surface, but you'll make a big difference. Just don't do it just before it rains. I'd suggest at least 2 days before rain, with at least 1 (but prefferably 2) watering before the rain.

Then sit back, wait for it to start growing like crazy...then you have to mow :(

As bombermwc said, yes you should water it in. Any solid fertilizer should be watered and broken down. I would lightly spray it three or four times a day for about a 3-5 days and that would do excellent.

Also, I would apply any kind of weed killer before you fertilize. Trust me!!! lol

I only use weed-b-gone before things start really gorwing, and then only put on some 10 10 10. Man when that fertilizer kicks in, any weeds that were around get choked out FAST when that bermuda grows like...a weed, bwahaha.

Same stuff I use lol. It seems to work great, with the exception of poa annua grass. It kills some of it, by not much. Do you or anyone else know how to get rid of this crap. I've been having to just sit and bend over picking this stuff out one by one

Ditto to what everyone has said. Water it in.

I recommend bending over and digging the stuff out of the ground. I'm not sure anything we use on our lawns is safe in the long run, but certainly anything designed to kill a living organism has potential risks, as we should have learned over time. Perfect lawns are a luxury we can't afford, for many, many reasons.

I do for most gardens, but not for my lawn with the exception of poa annua. IT WON'T DIE lol. . . I don't think weed b gone is that bad. I only use it once a year anyways

if it has weed killer in it you do not water it in immediately. this way the weed killer sticks to the weeds for a few days killing them before you wash the killer away