In article , eetmail-
says...
There's another good product for a few dollars by Aquarium
Pharmaceuticals called Plant Plugs. They're rockwool with a stretchy
netting to hold stems against the rockwool. You put the stems between
the netting and rockwool or into slits in the rockwool and then you bury
the whole thing in the gravel.

I use those. They work great.

--
Homo sapiens is a goal, not a description