I would not cover the rocks with soil. But if you get rid of weeds (and keep them out) in an area around the outside of the rocks, and plant something low and vining that will act as a groundcover, you could cover the whole apparatus with greenery. As maintenance, you could keep vegetation trimmed (or herbicided) back from directly over the grate.

I'd spray paint the white part dark brown to help hide it. It sticks out and catches the eye as it is. Min

Good point. I love the things that cheap paint can do.

You're right. The white part is concrete. I wonder whether paint would adhere to it. I guess I'll check at the hardware store. Thanks for the idea!

you can paint the concrete. I painted my patio floor and it held up great. The problem though would be with the water might loosen it. There is always concrete stain.

So I wonder why water flows out of it and not into it. Just from the looks of it I thought it was a drain. Just curious.

If you decide to paint it, I'd recommend using camouflage paint if there's a color that works for you. I've used the dark brown on small rocks that for one reason or another I don't want to be seen. It's very flat and blends well with dirt. The dark green blends well with plants, so I'd use that option if you end up growing vines there.

I've used the dark brown on cement blocks and it adhered fine. I can't say I've given it a long, weather-exposed test, though to see how it will wear. But it's easy to touch up.