Hello all - I bought a mini-dahlia with a beautiful, big purple blossom. Once that faded, I deadheaded and now the other two blossoms haven't fully opened, but they are already turning "ashen" on the edges (like they are ready to be deadheaded). I can tell they won't fully open or look anything near like the blossom I came home with. Should I look for any sign of pests on the leaves - I don't see any holes, etc. The pot is on a porch with part sun/shade.

I posted a photo of the blossom:

http://gallery.me.com/mikejdunlap#100101/0614090646

Thanks in advance for any help!