Does anyone know why my cosmos have started getting small blossoms with short petals?

I don't fertilize them much because I don't want them to flop over. I do deadhead every couple days. The blossoms on the right are fine, but the left blossoms are tiny, almost distorted and have very short petals.
Several of the newer blossoms are very small. Hardly any petals.
Also deformed. Some petals missing. I didn't see any bugs. Should I spray with Ortho Max or Sevin anyway?
  11 answers
  • Douglas Hunt Douglas Hunt on Jul 05, 2012
    Very weird, OC, but when I click on your photo it enlarges to a photo of a door. Anyway, aphids are a possible cause of distorted blossoms. Give your plant a good blast of water and see if that gets rid of them.
  • Sheri B Sheri B on Jul 05, 2012
    When I did the picture mine did the same thing, got a door. I agree with Douglas, there must be a bug in the flower. do as he says if that does not work then try an organic pest spray. Walmart carries a brand but I don't remember the name.
  • Organized Clutter Organized Clutter on Jul 05, 2012
    That door is not even my photo! I will check for aphids.
  • Dee W Dee W on Jul 05, 2012
    Ha!-that door is from the "Father's Day gift for my geeky husband" post. Your flowers are very pretty, hope you get this solved.
  • Vicki Vicki on Jul 05, 2012
    i love those pink and dark pink colors. i used to have lots of them but no more to come back for years. do not know why. boo hoo.
  • Miriam Illions Miriam Illions on Jul 05, 2012
    That door thing must have been some kind of weird bug (no pun intended). I clicked on the photo and got a flower. Let me know if you still see the door.
  • Organized Clutter Organized Clutter on Jul 05, 2012
    I removed the door photo and reposted new ones. I used my ipad for that photo. Not sure what happened.
  • Miriam Illions Miriam Illions on Jul 05, 2012
    That is bizarre! I'll make sure we look into this. Thanks :)
  • 360 Sod (Donna Dixson) 360 Sod (Donna Dixson) on Jul 05, 2012
    Try holding one of the flowers over the palm of one hand while tapping the bloom either against the palm or with a pencil. Thrips are another bloom disturber. If it is them, they will fall out of the bloom and onto your hand, they are tiny little critters and will scurry away pretty fast. I couldn't tell from the pictures if there is any spotting discoloration on the leaf blades. Which could be a sign of either the thrips or aphids . Try a good pesticide application for either or.
  • Tan5227879 Tan5227879 on Oct 27, 2016
    It could be plant virus, so any spaying will help. Just remove infected plants to avoid infection spreading.