Cyperus papyrus

can these plants be planted slightly (2 to 3 inches) underwater?

I have mine where the roots are underwater but the crown is right at the top of the water.

They can handle being submerged so long as they are tiny little starts. Big strong healthy ones can go quite deep I would think, I know we had them more than 6" at times.

The reason I asked is because I set these giant planters on top of concrete blocks and I can't really move them up as they are too heavy. The hight as is is a few inches below the water line. I dug these plants out of my low area where things are pretty wet during the rainy season in the summer. There they keep right on growing even as things dry out but they lived in the shade. Now they are transplanted into the pond in full sun and the existing stems are turning brown. I think it's sunburn.

I'm just wondering as to what's going on in the root system as I don't see any new sprouts coming up out of the water. Normally these papyrus plants grow like monsters in one season. I have a feeling that between transplant shock and the full sun they're just taking their time in getting established in their new watery home. We'll just have to see.
Fred

Did you rinse to roots off really well? They shouldn't have any problem going from the ground to the pond unless there was a ton of damage to the roots and they're growing anew or you have a lot of organics or potting soil around the roots that are making them rot. If there was a lot of broken roots that went in there with them and they're rotting, that could be a problem as well.

No, I didn't rinse anything. I just stuck what I was able to get out of the hard ground into kitty litter and put them into the water. Where I dug them up the ground is black muck but hard as rock when dry. I probably did damage the roots quite a bit but normally things recover very quickly when given a chance. I never even thought about rotting roots though. I'll just have to give these plants some more time.
Fred