Weeds are a constant.
Even if your neighbor didn't do what he's doing, seeds would blow in or be dropped in by birds.
Won't ever be free of weeds. Not ever.

Sure, there will always be weeds. No yard is immune to seed dispersal. I pull every weekend. But there is definitely a difference in weed sprouting 5-8 feet from the property boundary ....you should see the weeds fly when he is out there!

I'd just mow whatever grows in that strip & be done with it.

Hi purpleinopp,

The area is mulch and the weeds that are coming over are very low groundcover type weeds (with lots of seed), so mowing wouldn't even touch them.

I just checked with a landscaper acquaintence who recommended a pre-emergent (I try not to use chemicals, so I will use ground corn), applying damp newspaper, and lots and lots of coarse mulch (it is mulched already with cypress, but obviously too it is too fine and too little). If that doesn't control it, he recommended installing a vegetative barrier.

Use a pre-emergent herbicide. Apply according to directions.

Are you able to add a pic of the area? I'm not sure I'm picturing this correctly. Are you and your neighbor on friendly terms? If they were aware of your concern, would it be possible for them to do their side any differently? It might be easier to do a single plan for adjacent areas, than to have one area in conflict with the other.

Contrary to the expectations of many people mulches do not totally prevent weeds from growing. Mulches can aid, help, with unwanted plant growth, but seeds can, and do, germinate in mulches when conditions are right. A properly applied mulch can keep unwanted plant growth from the soil the mulch covers as well as aiding in soil moisture control as well as aid in keeping soil temperatures more even as well as adding (if the right mulch is used) organic matter to the soil.
But mulches can also provide a good nursery for "weed" seeds to germinate and grow in unless the gardener takes steps to prevent that such as lightly cultivating the mulches periodically which will disturb the rooting of these seeds.
One could spend money on some kind of pre emergent, also, but I'd rather spend my money on new plants rather then stuff that prevents plant growth.

This post was edited by kimmsr on Tue, Nov 26, 13 at 7:19

Yes, that's what I meant by "in conflict." If there was a mulch that would prevent weed seeds from sprouting or being able to grow, it would be "the mulch" everyone used everywhere.

purpleinopp and kimmsr...thank you for your responses. I will get a photo tomorrow and hope to upload it (never tried it here). My neighbors and I are on very good terms. He often asks for gardening advice and when he was complaining to me about the weeds in HIS yard, I suggested mowing with a bag rather than using the weed eater to prevent dispersal. He agreed that using a weedeater was making the problem worse, but he has yet to change over to a mower. I think it is easier for him...he admits he isn't a "lawn person". I don't want to push the issue - they have been good neighbors.

Maybe just doing the weed-eater more often, before seeds can be formed, could help? I like for things to be as easy as possible too! It sounds like you don't have any lawn to mow? Sometimes the easiest thing to do is zip over the part of the neighbors' yard that's bugging you. Our front yard meets another awkwardly so the convention has always been for both of us to mow this one whole part each time, so the grass doesn't change heights in the middle of a single, small patch. IDK if any of that applies. As long as nobody is offended, like you said. Weeds shouldn't cause THAT much trouble. Pics usually solicit all kinds of ideas from which to choose!