The ropey grass is Bermuda or Devil's Grass. The problem with it is that it does indeed grow deeply underground, then will come up, spread out and so on until it has taken over everything. People will warn you not to break it up as you will just multiply the plant. The only thing that you can do is apply RoundUp to what is above ground and if you're really energetic, dig down the the ropey stuff, apply RoundUp and personally I'd leave those places opened and exposed. Spraying RoundUp on the grass itself often does not travel far enough to kill off the ropes that continue growing under the soil. Don't even bother attempting to pull it up, you will end up with very sore hands and joints. Many people just end up fighting this stuff all the time. If that area isn't really being used to grow anything, I'd be tempted to put down Vegetation Killer. Nothing will grow there for a full year but that may not matter to you. Bermuda is a warm season grass that is grown as lawn in the Palm Springs area of CA because it can take the heat but come fall it dries out so the residents scalp the Bermuda, and reseed with annual rye and come March, the Bermuda starts coming back in.

Putting down black plastic, cardboard, landscapers cloth, or newspapers will NOT deter it, it will just grow sideways to find a source of sun. It can be a real bugger. Perhaps someone else has come up with a great idea for killing the stuff off, although they'd be a billionaire if they did find a cure. It's just a constant garden headache you must keep an eye on. It loves water by the way so if you can eliminate as much moisture as possible perhaps you could keep it from expanding.

Not the bermudagrass I know.

Here's some ID info from University CA, Davis.

http://www.ipm.ucdavis.edu/TOOLS/TURF/TURFSPECIES/bermuda.html

Beyond that, if it is Bermuda, it is very tolerant of drought. That is, it can tolerate extremely low water, brown out so that you think it's dead, then it will reactivate when it receives water.

Whatever it is, I seriously doubt it killed your peonies.

Here is a link that might be useful: ID bermudagrass

Thanks you guys...I know about the peonies..the peonies already had a strike against them not getting the sun they wanted..but I couldn't blame myself now!...got to be the weed...

I know pulling up was a mistake..but I got a perverse satisfaction of trying to kill the bugger..of course..it will get the last laugh by muliplying 10 fold...

Not sure what I'm going to do with whatever it is....My original plan for the plot was to move the 4 lttle plants I have and then get the area ready for next year by rototilling and using a weed barrier..I don't want to move the grass with the plants..

Again..thanks

Highly unlikely you would find Bermuda grass in Massachussets, but you would and could find quack grass. The long, ropey, tough underground thing is called a rhizome and that is how quack grass spreads. Around here I see a node about every 6 inches from which roots and new growth starts. I have not seen quack grass kill a plant yet although I have had these rhizomes so intertwined that the plant had to be dug up, cleaned up, and replanted.
Quack grass does really like the nice, soft, nutritionally well balanced soil of the flower garden and will fill in that bed if allowed. The most bestest way to stop that I have found is 10 inch aluminum flashing inserted vertically into the soil between the flower bed and the quack grass lawn. Janet Macunovich, over across the state from me, prefers plastic carpet runner.

A quick call to my extension office informs me that there is Bermuda grass in my area..According to her, some people have been sucessful with it, some people like to treat it as an annual, they keep it for 1 season..let it die, then start all over..

Whatever this is, it is not going to be fun getting rid of..

If it is a true grass, Fluazifop is a chemical that will take it out of a desirable broadleaf crop PROVIDED THAT the label lists BOTH the pest and the desirable plant in the appropriate sections. Precise plant ID and application technique make the difference between success and disaster.

Malorn, it doesn't sound as though you have an annual grass, or grass tender enough it would be treated as an annual in your climate. You might want to look up more aggressive quackgrass....

Thank you guys...I'm looking up everything and sending a piece to my extension office..I never thought that I would use their service, but because I really want to rid myself (if possible) of this stuff..acurate ID is necessary as suggested...

I'll post whatever they come up with..