How Do I Fill in Bare Spots in my Newly Planted Lawn?

Seeded grass is new. You can still see bare ground between
the new emerging and growing grass plants. This is normal.
If there are still many plants in each square foot of lawn it will
 fill in nicely after mowing and fertilizing.

Q. I wanted to ask you about my newly planted fescue lawn.  A few months ago, I asked you to give me a step by step project in replacing the old lawn in the house I just moved into.  I have followed the steps and have so far seen nice results.  I laid seed down on the 17th and from the pic I hope you'll agree, things are shaping up nicely.  There are sure to be spots that I didn't seed as even as others, so my question is, when/how do I go back and fill in those areas?  Any other opinion from what you see in the pic?  Thanks so much!

A. It looks good. The open areas between plants are to be expected. If it is open enough at this stage so you see bare ground I would not worry about it. The grass grows straight up in the beginning. As you mow, the grass plant will begin to tiller, or create side shoots, that increase the density of the lawn.

But if you are talking about distances between plants of several inches or more then you will need to reseed in those spots. If you reseed the entire lawn then you will waste alot of seed. Try to focus on those spots that are really open.

Dont worry about spots that have scattered grass plants in them. They will fill in. If this were me I would now apply another light application of fertilizer, probably straight nitrogen if you applied a complete fertilizer at the time of planting. This would be a very light application.

If you use 21-0-0 I would put down about two pounds for every 1000 square feet. I would then (if you have time) soak some seed in water (put a little bit of 21-0-0 in the water) for a few hours, drain it and let it dry overnight. In the morning when the seed is dry to the touch, broadcast the seed in the open area.

If you soak the seed and let it dry too long you will kill the seed. The seed has to imbibe water (like a sponge) let the surface dry so you can spread it but not too dry so the seed loses its imbibed water. The water soak with a little nitrogen will cause the seed to "explode" with growth. You will see what I mean if you do it.