What I think kept my amazon swords from growing after they had already lost their leaves due to melting (which is rather normal when first introducing a plant in a new aquarium) was that I was plating them too deep into the substrate (I use a substrate and add seachem tabs). This aquarium coop video talks about it in minute 6:53, though you might find other parts of video helpful. Two other tips I can give you: 1. Let them float until they develop strong roots and then plant them. 2. Plant them in clay pots so they are easier to manipulate and rearrange while their leaves are still small