How to stop grass coming under fence?

Spray it with a mixture of vinegar, salt and dawn but only the what is on your side of the fence or on your property.

Mix 1 gallon of vinegar, 1 cup of salt and 1 tablespoon of dawn.

Use a gallon sprayer and apply on a sunny day in the morning so this has a chance to cook the grass all day long.

But to keep civil relations with the neighbor I would talk to them first.

spray it with a grass killer that is what I do because my neighbor's grass and weeds come under my fence

Great idea from Mogie. You would need to reapply the mixture tho. Dig a trench slightly below the lawn level. Put down some plastic sheeting and fill with pea gravel or marble chips.

Vinegar is my best garden friend. It kills everything. You will have to reapply though that is true.

We asked out neighbors if we could mulch our fence line, and it's been great!

One idea would be to trim it if you can once a week, otherwise here is some other tips: https://www.youtube.com/watch?v=1NKY9bihmzw

Hello you might consider chemical herbicides or— a weed dragon if the fence is metal .

Spray with grass killer

Is the fence yours or your neighbor's? Most towns require a small setback for fences from a property line. If the fence is yours, you probably have some property on the neighbor's side you can do what you want with. If it's the neighbor's fence, some of their property might be on your side. Are you on good terms with them? Discuss your concerns and possible solutions.

You can put a barrier along the fence or spray with a weed inhibitor.

I would spray right along the fence line with a grass killer.

I would dig down at least a foot along fence. Bury some sort of barrier, pressure treated planks perhaps

Put screens under there or boards ,or logs something to block the space

I would chat with the neighbor first before spraying anything on it, especially salt, as they may not take too kindly to you killing their grass.

Hi Linda, I use this product and it looks and works great to keep the grass from coming through,

https://www.lowes.com/pd/Perm-A-Mulch-Rubber-Mulch-8-ft-Brown-Landscape-Edging-Roll/3608720