Do you know what type of plant the clump is? It's not something I'm immediately familiar with.
I see an anubias on the right that shouldn't be planted in the substrate. I think bottom left is a kind of java fern, which again shouldn't be planted. They are both rhyzome plants, and you tie the rhyzomes to something like a rock or piece or piece of driftwood. The other plant on the left is water hyssop and that's the only plant that is obviously a root plant that can be planted in the substrate.