Barrier material will work, as in Bamboo barriers.

Heavy and deep nursery pots will work, if you cut out the bottom and bury them in the ground.

Root pruning will work.

All of these methods are options, but they aren't ideal.

My favorite method, for display beds, borders, etc., is to keep reserve plants somewhere in nursery beds. When the display plants get too big, I dig them out and replace them with smaller, but still mature plants. Then I divide the big ones, concentrating on using the perimeter of each clump, and grow them on in the nursery beds.

FYI, "hamain" is probably 'Hameln.'

Thanks for the suggestions. Could you describe a Bamboo barrier? I'm not familiar with that. I've never seen these types listed as "invasive," but they surely are -- at least in my yard, and without any attempt to provide ideal growing conditions! I expect I'll have to Roundup the area around the border, put in some kind of barrier and replant the lawn grass eventually.

Bamboo barrier is simply heavy plastic or poly sheeting, ranging from 18-30" deep, and 40-60mil thickness. You dig a trench and bury the stuff around the area you want to contain. Leave a couple of inches exposed at the top.

I see that you are having a problem with your ornamental grass. I wish I had that problem. I have tried to find locally and can not. I am told that it does not seed? Would you be willing to trade or share some of yours? You can check my list and see if there is anything that you might want to trade for or I would be glad to pay postage. Thanks in advance.

Yaeh, what jerryngeorgia said! I want some grass, please check my lists.

Again, thanks for the info. Sorry, I'm not in the plant/shipping business. I ordered my original one (tiny) clump of fountain grass in 1995 from Limerock Ornamental Grasses, Inc., 70 Sawmill Rd., Port Matilda, PA 16870 (814-692-9848). Their catalog offers many types of orn. grasses and the listings/descriptions are zone-specific -- if they are still in business. Good luck!