Here's what happens when you let some freebie grass grow that came in a plant you bought at the pond store:
I bought an arrowhead plant a few years ago and this tiny grass tagged along home. This spring I realized this stuff is going to take over the whole pond if I don't do something about it. It was completely filling one edge of the pond and had grown a massive mat of roots that completely encased a whole bunch of rocks and was headed for the bottom of the pond. I bet this mass weighed several pounds by the time I managed to wrestle it out. It's hard to judge from the picture but this is almost two feet long and the roots went down about 18 inches into the pond. It was between the rocks and around the rocks and between the liner and the rocks... it was everywhere! And it had started creeping out of the pond and was mingling with the vinca that lines the pond edge. I had to completely dig out about a four foot long section of that and meticulously separate out the vinca from the grass and replant the vinca. What a job! And there's a small section of the edging that I need to get to from the inside of the pond - that will have to wait until it's warm enough to climb in!
Moral of the story - never plant something if you don't know what in the heck it is!
I bought an arrowhead plant a few years ago and this tiny grass tagged along home. This spring I realized this stuff is going to take over the whole pond if I don't do something about it. It was completely filling one edge of the pond and had grown a massive mat of roots that completely encased a whole bunch of rocks and was headed for the bottom of the pond. I bet this mass weighed several pounds by the time I managed to wrestle it out. It's hard to judge from the picture but this is almost two feet long and the roots went down about 18 inches into the pond. It was between the rocks and around the rocks and between the liner and the rocks... it was everywhere! And it had started creeping out of the pond and was mingling with the vinca that lines the pond edge. I had to completely dig out about a four foot long section of that and meticulously separate out the vinca from the grass and replant the vinca. What a job! And there's a small section of the edging that I need to get to from the inside of the pond - that will have to wait until it's warm enough to climb in!
Moral of the story - never plant something if you don't know what in the heck it is!