Where is the dividing line? It all looks the same to me.

is it just that 18" or so along the drive? Just ask neighbor to let you do that bit so it all matches (or ask neighbor to do your whole lawn).

The scalped, yellow grass is the neighbor's. Why not ask him if he would like you to cut his little strip when you cut your front? If he doesn't want that, just put a strip of brick size pavers from your patio to the sidewalk for a mowing strip.

I have a similar small strip and I just cut it with my lawn so it all matches. The neighbor is fine with that. I don't do their edging though. :)

I have a slight feeling the neighbour is doing it on purpose due to another issue, I had mowed it all equally and they still mowed it short the same evening.

Then use the small concrete colored pavers, with the outside edge on the lot line. If you recess them, you will be able to put the lawn mover wheel on the strip. That is a very passive-aggressive ploy on his part.

"Due to another issue." Please tell us more ....

Was it previously discussed that youd be mowing that section?

It seems like there may be a concern about property line ….if it blends with your lawn it could be interpreted as your property…even legally…over time…to avoid that you may need to add a minimal element of separation …clearly defining your property line…anything more will add to your maintenance obligation and throw off the nice balance you have now

Even a pound in strip in green to match your lawn would do….

I will probably do the paver idea that way I can also mow easily, thank you!

Yep. Welcome to American lawn care. "Scalpin' for Jesus" as I call it. Because I guess 'scalpiness is next to godliness' or something? It's so utterly idiotic I grasp for explanations. The lawn is better looking, far more resistant to weeds, and needs to be cut less often to look 'level', if it is cut higher. It's such a no brainer.

Funny thing is noticed in maritime climates (NZ, UK) they scalp their bentgrass or whatever lawns. But bentgrass is meant to be 'scalped' - and those climates are what they are. Summers with frequent rain and seldom above 80F/28C. The only way in my opinion to have an environmentally sustainable lawn in most climates in the CONUS with most grass species is to let the grass grow long and strong. My lawn, which I cut at the highest setting of a Kubota BX MMM, is always the last to turn brown in dry spells and after freezes in early winter. I have been unfortunately tearing up huge swathes of it to put in french drains, and the root systems are huge...you get a chuck of soil sometimes 5" deep. It's of course recovering quickly in places where I put it back over the gravel and fabric. The average husk of dead earth covered in crabgrass around here - i.e., most of my neighbor's 'lawns' - would just be ugly chucks of clay soil after this process.

I wouldn’t add pavers, as now there will be two strips breaking up that area, calling even more attention and feeling more random.

Your yard could do with more interest anyway, so perhaps consider a planting bed. Head to a nursery, discuss your preference around the look and you’ll get lots of helpful advice.

I would dig out the lawn on your side.

Get the your hose out and line it up. Start digging a curvy edge to your side.

Fill in with hostas, all sorts of hostas, they come in all colors. They fill in beautifully, they get to the size of small bushes. No maintenance at all. Come up every year.

I agree about the scalped grass! I really prefer the lush look of a taller maintained lawn.

If I do more landscaping, how would you shape the new bed? Im not the biggest fan of curved edges, would something more linear work in the space? I like the hosta and ornamental gradd idea!

What about a little row of shrubs like the ones under the front window?…anything tall would be out of sync with your setting

I'm surprised your neighbor doesn't pave over his strip so he doesn't have to mow it! And the neighbor may well have mowed it, even though you already had, in order to avoid any issues with you claiming adverse possession over that strip. So it may not be related to any past issues.

The photos aren't helpful in terms of the size you have to work with, but you could certainly have a straight edged bed down to the sidewalk. But won't you then still have a teeny bit of irritatingly mowed grass on the boulevard? Unless you really are dying for more foliage or flowers, I'd be tempted to let this go if it can't be worked out with a simple conversation.

If adverse possession worries are what's driving this, there's a very simple fix. The neighbors just need a one or two sentence agreement that OP is mowing the lawn for their joint convenience, and fully recognizes that strip as the other neighbor's property. An email should be sufficient.

would your neighbor let you mow this strip when you mow your lawn? then it would be same length.

You have a nice paved area in front of the steps - and such a small bit of grass, that I would be inclined to forget grass and do a bed of low growing "carpet" evergreens, hostas, stone, a dwarf flowering shrub or two, bulbs, and so forth. You might not want flowering things, they can be left out. You can make the plantings as minimal or full as you like, but maintain the straight edges for your "clean lines". Use pavers to match your house to edge sides and front.