First this can only be done if you are rogue/druid since you need to have steath ability and also Freya has to be alive ( i think herbs don't respawn when she is dead ).
So if u are saved to same raid and Freya is alive then this is a nice way to make some gold ( im doing this every reset if Freya is still up on her legs ). This can be done on HC and i think on normal ( never did normal Ulduar so i dont know ), and if u can do it on normal you can double gold income
Well if you watch video you'll see that i got 4 Frost Lotus plants in few min, since on my srever Frost lotus sells fo 40g then this is a nice income. I average 3 per on run then i log out since it take 30min for plants to respawn. But if u can do it on normal also u will probably double your income.
Tips:
Remove all of your gear so if you die you don't lose durability and if there are Frost Lotus plants near mobs leave them for last like i did since you will probably die
[ame="http://www.youtube.com/watch?v=qpY5yX4tZK8"]http://www.youtube.com/watch?v=qpY5yX4tZK8[/ame]