What to plant in a narrow bed along a garage?

Hello everyone! We have a 30cm planting strip (yes, really that narrow. This results from an installed irrigation system) along the garage of our neighbors (9m long...). We would like to plant it! Preferably with nice ground covers that stay "narrow" or also tall-growing plants. However, these may only become about 0.3m wider than 30cm so that the robot can mow underneath without obstruction. It would be nice if they didn't grow much "deeper" either. Do you have any concrete ideas about what we can plant there?

I would plant grasses.

Ground cover
Thyme, Phlox, [Immergrün]

However, these may only become about 0.3m wider than 30cm, so that the robot can mow underneath unhindered. It would be nice if they wouldn't grow much "deeper" at all.

I have the feeling everything has to subordinate itself to your robot.
I think Eunymus Fortunei is quite nice for such corners. It is a bushy ground cover, about 30cm high (ours is already 50). You can shape it (but you don't have to) and in my opinion it looks very elegant with white and anthracite. It is low-maintenance and does not spread wildly.

Do you have sun there? If yes, it might possibly be a suitable place for wine

Exactly... wine thrives wonderfully on a warm wall..