Board Thread:General Discussion/@comment-24133975-20140418161945/@comment-24133975-20140418223823

Hi there Nstuff. In order for Plantera's Bulb to spawn you need to defeat 1 Mechanical Boss. If you haven done that before the 1.2 update you may have to do it again. There's 2 ways you can go about finding the Bulb. The first is to use your mini-map to spot the little pink pixel that should be the Bulb in the Underground Jungle and the second is to farm for it, which is done by making long strips/tunnels in the Underground Jungle.

You can find more information on the Bulb here:

Plantera's Bulb

And here:

http://terraria.gamepedia.com/Plantera%27s_Bulb

I hope this helps! :D