Nuthin, they'll more than likely fall off after being exposed for awhile. No worries, theres lots and lots more for them to drink from.
CorrectI believe that's the point of fabric pots. I use them too with great results. I think its called "air pruning".
Man they look great.
This is my first grow but I took the time to set it up the right way first, did lots of test run's tuned everything in just right, so far I would say it's pretty perfect. Looking to flip to flower around the last week of this Month. My expectations for a 1st. grow are very high and I'm hoping for little problem's.