I think there's confusion over the 6th Lightning Lily. Ivy gave me mine when I completed Goal 10 by collecting my first Static Sap. Note that Static Sap is not a guaranteed drop; I think I had to collect from Lightning Lilies 4 times to get my first Static Sap. I had immediately collected from my first Lightning Lily when I received it; and I had put a couple more Lightning Lilies into storage when I got them (in order to move them away from the Potion Shop); so I definitely did not follow the complicated procedure that other people have listed in order to get my 6th Lightning Lily.
However, Storm8 still has improvements to make.
1. It's unfair that if you immediately plant a Lightning Lily when you collect it from the Potion Shop, it's immediately available to collect; while if you put that Lightning Lily into storage when you collect it, then when you bring it out you need to wait 6 hours to collect. I often put things into storage after collecting them because it's easier to then move them to the other side of my realm, and doing that shouldn't cost me 6 hours.
2. Since they are locking the Potion Shop after creating 5 Lightning Lilies, then should also lock the StormStalk after gathering the 5th Lightning Seed. There are a lot of people who spent a lot of resources making a 6th Lightning Seed and now they can't use it for anything. (BUT NOTE: collectors may want to create a 6th Lightning Seed even if they can't use it to create a Lightning Lily, so collectors may disagree with locking the StormStalk. Perhaps an up-front warning that any Lightning Seeds after the 5th, will only be collectors items, might make everybody happy.)
This event is very expensive in energy usage, but I think it's the random rare drops of the Static Sap that are going to kill me. "Real Life" is going to prevent me from playing much in the next few days, and that's fatal when the event has random rare drops.