I built the fence, planted the seeds, waited the 6 hours (with Fertilizer), had a worker (So they all were very healthy) then when the farm was glowing all green letting me know they were ready, I harvested them and got nothing in return :(

Is there a specific time you're suppose to wait before harvesting them?? The event notice made it seem like you grow then collect but I got nothing unless I missed something, checked all banks multiple times, I checked everything, even logged out then back in and still nothing... I was looking forward these trees :(

You should have gotten the item [Manor] Cherry Tree. If you did not get it, please send a ticket to support.
Here a pic of how they should look:

Yeah, sadly never got them, I'll put a ticket in

I did not read the whole post but this may help?

[Event] Cherry Trees for Your Manor? | Black Desert Southeast Asia (playblackdesert.com)