Umbral

The Umbral mutation sits near the very top of the value ladder with a massive x30 sell multiplier, the kind of number that single-handedly transforms a crop from pocket change into a jackpot. You can spot it by its distinctive double-particle look — it emits both yellowish-green and purple particles, and the trigger behaves similar to Bloom, meaning it lands as an appearance-based mutation rather than a passive weather coat.

Because it is a Bloom-style application (its in-game art ties it to Bone Blossom Umbral), Umbral is most powerful when it lands on a crop you have already loaded with other multipliers. Mutation multipliers in Grow a Garden stack, so an x30 layered onto growth and rarity mutations on a high base-value transcendent crop produces some of the largest single sales in the game.

Is it worth chasing? Absolutely, but treat it as a finishing touch, not a farming strategy. You will not see x30 often, so the smart play is to reserve your best-prepared, highest-base crops for the moment Umbral appears — landing it on a cheap plant wastes most of that enormous multiplier. When it does hit something valuable, sell immediately.