I will tell you in this post when to cut a amazon sword plant. If you have a Amazon Sword Plant then you may have seen a stem branch off and start to grow some new plants. Well you don't want to cut them off to soon, I have learned this the hard way and have killed them in the process. You want to wait until the plants have a nice strand of roots coming off them. You can really never be to late to clip them off, the stem acts as a source of nutrients to the plants.
You can cut the stem and close to the pant on each side but not the actual roots or leaves, then you want to place into a small clay pot with some potting soil with some gravel on top of the soil. If you want to do soil make sure to soak it in water. If you just place it in the pot by itself it will float and break up all over the tank.
After placing in the tank just let it grow. Don't try to just place them in the gravel or sand that you have. You need the potting soil to help your amazon sword plant grow.
I use miracle gro soil because the miracle gro is so beneficial for the plants and it won't hurt the fish. I even add a teaspoon weekly to my plant tank and it does great and the fish don't mind it. Remember with the plants don't add to much miracle gro because it can kill or burn the plants and fish.