I was wondering if it was possible to get as much crimson nirnroot as possible then leave and wait a week or two before the nirnroot grew back. Any help would be appreciated. Thanks in advance.

Think it's written in the games books somewhere that Nirnroot is pretty much the only stuff that doesn't grow back. If it does, just wait somewhere a dozen times for 24 hours a pop, if it actually doesn't, just add that stuff with console commands if you really need it.

Too bad I'm on PS3. Console commands don't work for me and I'm talking about CRIMSON nirnroot in Blackreach. Does anyone have a map at least?

Yes the crimson niroot grows back. I believe it takes 2 to 3 weeks for them to regrow.

There is a map in the strategy guide but i have no way to post it. You need thirty and I believe there are 35 in Blackreach so mulitple trips are probably in order as some are very well hidden. Or try to find the map on the net.