Firefly Fern

The Firefly Fern is a limited Mythical crop from the Prehistoric Event, and two facts dominate its economics: it is multi-harvest and event-locked. Multi-harvest is the single biggest profitability lever in the game — you pay the unlock cost once, then the same plant keeps producing on a cooldown, so the true return is measured over the plant's lifetime, not per pick. That turns a one-time event grind into a long-tail income source, which is exactly what you want from a Mythical-tier plant.

Its triple typing as Prehistoric, Stalky and Leafy widens the buff surface considerably. Prehistoric-targeted event gear stacks with general Stalky and Leafy bonuses, so a Firefly Fern can soak up several layers of type buffs at once that a single-type crop simply can't.

For mutation stacking, prioritize the persistent, repeatable multipliers — sprinkler-driven Wet, weather Chilled, and any always-on environmental procs — because a multi-harvest plant benefits from them on every single cycle, compounding their value. Lock one in while the Prehistoric Event is live; once it ends you can't reacquire it, and a permanently-installed multi-harvest Mythical is a far better asset than the same Sheckles spent on disposable single-harvest crops.