Is this so called "event" where people are buying cheap sylestis just to sell them in order to get things over yet? I'd like to be able to start selling my pets again.

The release contest runs until June 10 @ 11:59pm.

As long as the pets you want to sell have a birthday after 5/20, they are safe to sell since they are not eligible for the release contest.

You can still sell your pets during the release contest, and ones that'll take place in the future.

There are a couple of things you can do that would discourage players with lots of disposable gold that would otherwise scoop up your pets for the release contest- or for other reasons because I'm not going to guess what other players are up to.

Namely:
For this release contest, try not to sell pets born before the cut off date (which would be 5/20).
Do not sell pets for under 10k publicly
For pets you wish to sell under that 10k baseline- sell directly to the user that wants it using their ID.

I should add that the base of 10k gold I'm giving is an example; it's not all that hard to make it quickly but it certainly spends fast, and when you're buying pets to release for a contest you're looking mostly for pets under 1k for public sale. After that source of pets is exhausted, that bumps up to 2k- 3k- 4k- and so on.
Speaking from personal experience- unless I have a literal mountain of gold I'm not going to be buying up pets enmasse at 10k a pop for a release contest and I'm sure other users would feel the same way.

Perhaps check the 'event' dates.
Don't sell pets for incredibly cheap publicly if you do not want people to make use of their right to do whatever they like with what they buy. :/

The Release contest Is just small part of the fest, I suggest doing as the others have said. And Have fun this is a Festival after all ^.^ if you want seeds to plant in your garden I have quite a few i'll gladly give you, they ain't Vul's Qit's or Lup's, but I'm sure you could trade them for those seeds