Originally Posted by Unregistered

You need those to evolve your 4 to 6 star Flower Knights.

I think they started to appear when the winter rose garden backtheme was introduced, so it probably was with the holly event (?).
All of the 4 colours can appear though they seem to be pretty rare. What they say doesnt seem to have meaning, at least i haven't heard any suggestion about it.
That's pretty much all i know about them

why do people farm 2-1 for secret gardens instead of just farming E-1/R-1 for event currency and secret gardens at the same time