There is editting a week and editing a diary. The edit week button is central at top, and visible. The edit diary button is nested in the "Settings"button at the top-right. With this one you can remove and add seeds, lights, tent, etc.
If something is corrupted, go in there, add your correct custom seed, then remove the old one. This should correct the diary. I had to do this when my lights showed up as some Fission something or other brand i've never heard of.