Plan on using palmetto leaves also. May want to cut plenty so they will brown off and you can use them later in the season to touch up the blind. Another tip is to cut willow brances now while they are still green, if you do that, the leaves will brown but will not drop off nearly as fast. If you keep the same blind year after year, the willow cuttings will grow if you stick them down in the mud and you can trim them year after year. The more you cut them the bushier they will get.
I have used them before in PAC. They block the wind very good. Don't put them too high up in your blind because you can't see through them. My favorite blind making materials are little bushes called 'mongs' or 'see-de-ays'. With one swift cut you can chop a small bush that will cover 3 to 4 feet of area. I usually cut them in the marsh near where I'm gonna hunt. That way I only have to ride a little ways with them in the boat. After a few years of doing this you might not have to put anymore. It will look like a bird's nest. Real easy to peep through too. Good luck. Don't let'em see you face.
your blind in the middle of cattail patch sounds great. If you use cut or whole roseaus they can take root and quickly create a living, rapidly growing, nearly unstoppable roseau field. After a few short years you can have acres of roseaus that you can't get rid of. Just a little fyi.
The palmetto leaves are a good wind breaker and a good camo.