When can I use 'weed and feed' on lawn that has just-grown grass from seed?

[Pan]

I've used grass seeds to fill up some bare patches and it's worked well - this was about two weeks ago and the new grass is up to about 1" in height. Would anyone know when it will be okay to use weed-and-feed? I don't want to 'burn' the new stuff, but the lawn does need dosing asap.

any ideas? I've tried DrLandcapeGoogle but nothing v clear at all.

tia

Just looked out the window. It's more like 2" plus now!

any idea?

I would leave it till next spring, personally.