The first time I saw grass clippings used was at Leamings Gardens in Cape May Court House in NJ. I was amazed at the health of the plants and the lack of weeds. I came home and used it in my gardens without problems. I now use different types of mulch in my flower gardens but we always use the grass clippings in our vegetable garden without problems, the clippings keep weeds down and hold moisture so watering is rarely an issue.

I mulch with clippings beneath my dahlias with great success. Just be sure that the clippings are from grass that hasn't been treated for weeds.....eg: weed & feed.

I concur. I have a small patch of grass in my front garden, which I mow with a push mower and rake the clippings right into the flower beds.

Heather

Whenever I mow, I rake the clippings right into the beds. I figure the nitrogen in the grass certainly can't hurt. I just make sure that there is no clumping. I do not use it in place of a standard mulch(in my case, shredded hardwood, as a thick layer of grass clippings doesn't have the same porousity(sp?) of standard mulch. I envision lots of root rot if one were to use a thick layer of grass.

I get grass clippings from our recycling center, so I'm not sure what's in them. It has not harmed perennials or vegetables when I mulch with these clippings. But when I bring other people's grass into my yard, could I be transmitting bugs or diseases to my lawn?

For the original question - I think it depends on whether your weedy grass has gone to seed before it gets cut. If allowed to go to seed and then blown in, yes it could cause weeds.
I used to use grass in my vegetable beds. First I put down a layer of partly composted straw to keep the grass from matting too badly. Then the grass clippings would go on top of that - part of the trick I think was to have it thick enough to block all light for germination to anything below it, but not so thick that water wouldn't penetrate. It worked pretty well. For regular flower beds I've always just used bark mulch but grass would work too as long as you have enough clippings coming to keep it a certain thickness.
Mary

I have Bahaia grass in my back yard and I bag so I can have free mulch.
FIRST though .I throw down gobs of newspaper,cardboard, and junk mail(no Shiny) It REALLY makes a difference with the papers and the worms love it!I have seen them do this elsewhere with only a few papers but THICKER is Better.Don't shred them unless you are putting them in a compost bin.Wet as you go.
Recycle those papers and cardboard boxes and make life easier!

I have used grass clippings in all my beds and in the paths between. It has helped us to get rid of chest-high careless weeds that covered the yard when we moved here in 2003. I don't know what I would have done without my neighbor's grass clippings.

Am now using cardboard and neighbor's newspapers to build new beds over bermuda grass. We have a very small portion of our yard devoted to lawn so gotta buy mulch for the new beds.

I've used grass clippings (our grass isn't perfect, so probably weeds) in a lasagna garden with no ill effects. However, I did see on a show on HGTV that even a little piece of grass blown into a bed can cause grass to grow.

Be careful, however, because too much nitrogen can result in lots of green growth, but fewer flowers. This happened to me a couple of years ago with Cosmos. They got huge, but I didn't have a flower on them until September!

I also saw that segment with Paul James who I think is fantastic but I did wonder about that one blade of grass thing.:~/
I just spent a fortune in sod and if that were true with Florida grass we could all save a bunch of $$$$$$ by sprinkling grass clippings to get a lawn! So it may be northern grasses that do that.Not sure.I believe he lives in Oklahoma.Certainly gives us something to ponder !

I'm in Texas and have sprinkled a lot of grass clippings about for mulch but have never seen any take root and grow.