Do you use Roundup routinely? Perhaps there is runoff from the Roundup? Do you use salt on the walkway during winter?

To avoid Roundup spray drifting, it is often recommended to cut the bottom out of a 2-liter bottle. Place the bottle over the weed(s), insert the nozzle of the sprayer into the neck of the bottle, and spray into the bottle.

I don't use Roundup much, and haven't tried this myself.

RoundUp damage. It's almost impossible to avoid drift of extremely small airborne particles....but I would also suspect that the herbicide travels through the pavers or the channels in between the pavers.

While it is possible the Round Up could be causing the problem it could be something else. I see two problems here. First is you are seeding in the spring. The roots don't have time to establish and go deep enough to survive the summer heat.

Second is the brick pavers are heated by the sun and are cooking the grass. The heat from the pavers will dry out the soil much faster and with the shallow roots on the new grass it just can't survive. Try planting the grass this fall and I bet you will have more success. Even then, this edge will probably need more water during the hotter parts of summer due to the heat of the pavers drying out the soil.

Your pavers are graded to drain away from your house which is towards the lawn. Even if you are not spraying roundup directly on the lawn, it is likely washing off the pavers into the edges of the lawn. The roundup also migrates into the seams of the pavers and into the base below which drains to the lawn.

Roundup washing off the pavers onto the lawn would not affect the grass that much.

However, if you just pour boiling water on the weeds, that will eliminate Roundup from the suspect list.

I think spring planting, foot traffic, and the sandy bed of the pavers soaking up too much water combines to make this die-off.

I think it must be the Roundup because we haven't had a real warmup here in NJ except a random day here and there in May.

I have my tank sprayer putting out a very concentrated stream of herbicide so it's hard for me to believe that I killed that much grass by getting too close to the edge of the pavers but I suppose it is possible.

Is it too late to rescue this area considering it is May 30th already? I will be watering this area way more frequently from now on as well.

For most herbicides a mist is better than a stream. Glyphosate works by being absorbed by the leaves of the weed which take it to the roots and kill the weed. Soaking the ground is not what you want to do. Next time try applying it as a mist but do this when the wind is calm. If needed you can cover the grass with a sheet of plastic while spraying to avoid overspray.

If the Round Up is the culprit more than likely whatever is brown is dead. You could cut the dead stuff out and try reseeding.

Try using White Distilled Vingear instead of Round Up.
It won't kill your grass, but it will kill the weeds.
I just pour it on full strength and the weeds die.
I have the same pavers that you have, LOl, in the same color.

i live in nj and i have the same brown patch on my lawn. i have had it for over 5 years and i do not use any weed killer

Why do you think the grass would be extraordinarily green just beyond the dead area?

What are you using for fertilizer?
How often are you using it?
Applying full bag rate every time?
Do you use a broadcast or drop spreader?

When you water does the water hit the pavers?
How often do you water?

I think ForsheeMS was on track toward the solution, but I'm wondering if the green and the brown are related issues.

It looks like there's a concrete border on your walkway, which could be leaching lime into the soil and changing the pH in that small strip. You can buy a pH test kit, test a sample of the soil at the border and compare it with soil from an area where the grass is growing well.

It could also be that the material used for the base of the walkway make the soil in the problem area too sandy/gravelly to hold enough water for the grass. The roots need several inches of good soil.

Maybe I should check the pH. Any recommendations for a soil test kit that's pretty reliable and one I can perform myself? I'm not sure the ones on Amazon are all that great.

I think the Rapitest kits are ok as long as they're fresh. You might also check at your local garden center to see what they have. You can also get a kit from Rutgers, or send them samples for testing. I didn't see how much the testing would cost, but it may be worthwhile to you because the lab may also tell you what you would need to do, if anything, to amend the soil for growing turfgrass. Worth checking it out.

Here is a link that might be useful: Rutgers soil test

Im also in NJ and Do Not use round-up any more and have a similar problem. I think it is the heat from the pavers or something from the pavers. I dont use anything apart from vinegar now. It's just probably got poor water retention next to the pavers and shallow roots, i would water it more.

That area of dense green does make it look like a fertilizer issue. When you spread the fert are you getting some on the walk and then sweeping it off? Maybe too much at that bend? Alternatively is there maybe crushed stone under a small amount of soil in that area?

I think schreibdave hit the nail on the head with the fertlizer comment.