On my forum I have a place for people that grow giant pumpkins to set up a diary that they can use to document their progress while they grow. I need to find a way to make it so that only the diary owner can make posts to their diary. What I have done for now is make a group called pumpkin growers and added people who grow giant pumpkins to this group. I set the permissions so that registered users can read the posts from this group but not post to it. The issue i see is that anyone that is in this group will be able to make posts to anyone elses diary that is in this group. How can I make it so that the owner of the diary has exclusive posting rights to the diary?

Short of making a group for each person I still cannot figure this out. Any ideas?

You would need to create a separate group for the diary owner to allow him/her to post in the diary. You can assign multiple groups to members via the Administrative panel on a member's account. Just hold down control or apple(mac) to select multiple groups from the list.