Editing Thread Why Cant I

 i am unable to edit the first post in my thread ?  can somebody please explain how to do it please.
 
thanks in advance..  
 
i can edit this one fine and could with the other does it have a time limit ?

 

http://forum.grasscity.com/gardening/1328592-bubbles-learns-how-garden.html
 
 I F .  i would like " bone meal and the link for it removed it deffo shouldnt be in the mix.
its on my 1st post.
 
thank you very much   

 

I doff my cap sir . thank you.