Txs in advance!

I'm sorry you have had no replies yet. I think we need more information.

1. Have you been in this house long enough to see the plant when it is green?

2. Were there any flowers or seed heads?

3. Is it all in one patch, or is it spread throughout the garden?

4. Are you sure the green plant is the same as the brown ones? It appears to me to be something different.

It gives the appearance of being some sort of flower bulb that has died down for winter. If you want to tidy it up you can trim off the dead leaves, but don't dig over it. Wait till spring and see what happens.

I am not sure what the green plant is but it doesn't really look quite like grass either. I would wait and see for that one as well.

LOL!! It is pretty darn hard to accurately ID what appears to be a deciduous ornamental grass in the middle of winter! But from the flat, flowing habit, I would make a wild guess of hakone grass, Hakonechloa macra (which is endemic to Japan).

And deciduous ornamental grasses are like deciduous trees and shrubs or herbaceous perennials. All the foliage will die back in winter but the root system is still very much alive and will regrow new foliage in spring.

It might make more sense to come back then and show your grass in actual seasonal growth to get a correct ID instead of just a guess :-)