If your leaves on your cannas are rolled and stuck together then your plants are infested with canna leaf rollers. There are two different types, but the symptoms and treatments are the same.
The adult insects lay eggs on new leaves. In the caterpillar stage they "stitch" the edges of young canna leaves together with a silken thread so they won't unfurl. This is the perfect hiding place as the caterpillar eats the leaf it's rolled in.
If you can open the leaf then remove the worm. Or if lots of leaves are already badly chewed up, snip them off and step on them. Make sure you throw them in the trash just in case there are any eggs still remaining.
A insecticide systemic also works against these worms. You just sprinkle it on the ground and water it in. The plant absorbs the poison and when the worm bites into the leaf, it will take in poison with each bite and eventually dies.
Second Segment: "Root Bound Plants"
If you have to replant root bound plants, there are a few facts that will increase the survival rate of your plant.
1. First water the plant well.
2. Hit the side of the plastic container with your fist or a rubber mallet. Do this on all sides.
3. Then gently tug and pull the plant out of the pot.
4. If you plant is real root bound, you do not ever want to cut the roots. You will want to loosen the roots my taking your figures and gently loosen the roots as not to break them.
5. Plant with organic matter. I mix half existing soil with half new soil.
6. Water in Root Stimulator.
7. Keep the plant moist and in a few weeks, fertilize with an all-purpose fertilizer.