Since Update 6, mutations stack and multiply together — they are no longer limited to one per crop. By multiplier, Fire (10×) is the top weather mutation, followed by Cosmic (8×), Honeycomb (6.5×) and Rainbow (5×). Starfall (11×) is pet-only and is the one mutation noted as a universal stacker. Stacking several mid-tier mutations on one crop usually beats chasing a single high one.
Mutations are the single biggest lever on your income. A crop's payout is Base × Mutation stack × Ring × Quantity, so a multiplying mutation scales the entire equation — far more than a faster grow time ever could. The table above is the same data that drives our mutation table & calculator; the sections below explain how each mutation behaves, how to get it, and how to remove one you don't want. Multiplier values are community-reported and can shift after patches, so each carries a confidence label.
This is the most important — and most misreported — mechanic in the game. Before Update 6, a crop could hold only one mutation. Since Update 6, mutations stack and multiply together. Several competitor guides (including Pro Game Guides) still describe the old "one mutation only" behaviour — that line predates Update 6 and is outdated.
What stacking means in practice: if a crop has Fire (10×), Cosmic (8×) and Rainbow (5×) at once, the mutation portion is 10 × 8 × 5 = ×400, before ring and base are applied. Put that crop on the Outer ring (19×) and the multipliers compound again. You can reproduce any combination in the income calculator — it multiplies selected mutations exactly the way the game now does.
Mutations come from three sources:
Weather events apply mutations to crops that are out during the event — Rain → Wet, Snow → Frozen, Heatwave → Fire, and so on. These rotate automatically and are the main free source. Sprays from the Gear Shop apply a chosen mutation on demand (for example the Rainbow Spray), trading cash for control over timing. Pets apply mutations passively: the Starfall Griffin grants the exclusive Starfall mutation, while the Kitsune, Hydra and Mammoth apply the Farm mutation (4×) — the same effect the Trucker Spray gives. For which pets are worth it, see the pets tier list.
The Farm mutation multiplies sale value by 4×. Unlike weather mutations, it doesn't need an active event — you get it from the Trucker Spray (a Trucker Event reward) or by running a Farm-mutation pet. Because it stacks like any other mutation, it's a reliable, always-on multiplier to layer underneath your event mutations. Its multiplier is community-reported.
Stacking is usually good, but a low-value mutation can occupy a crop you'd rather re-roll. The Acid Spray strips mutations off a crop, letting you reapply a better combination. Use it when a crop picked up a weak weather mutation right before you wanted a high-value one. Behaviour here is community-reported and can change between patches.
Sources: Pro Game Guides — mutations & multipliers (note: their "one mutation only" line predates Update 6 stacking) and allthings.how — multiplier rankings; game identity and the offline-earning loop are confirmed on the official Roblox page. Multiplier values are community estimates and can differ between sources — we label every one by confidence.
Yes. Since Update 6, multiple mutations on one crop multiply together — there is no longer a one-mutation limit. For example Fire (10×) plus Cosmic (8×) gives ×80 before ring and base. Many older guides still say "one mutation only," which is outdated. Our calculator stacks them correctly.
By multiplier, Fire (10×) is the highest commonly available weather mutation, with Cosmic (8×) next. Starfall (11×) is higher but pet-only (Starfall Griffin) and noted as a universal stacker. In practice, stacking several mutations beats relying on any single one. These multipliers are community-reported.
The Fire mutation is applied by the Heatwave weather event to crops that are out while it's active. Weather events rotate automatically, so keep crops planted to catch them — or use a Gear Shop spray when you want a specific mutation on demand.
The Farm mutation multiplies sale value by 4× and doesn't require an active event. You get it from the Trucker Spray (a Trucker Event reward) or from the Kitsune, Hydra or Mammoth pets. It stacks with other mutations, so it's a dependable always-on multiplier.
Use the Acid Spray to strip a crop's mutations, then reapply a better combination. It's most useful when a crop picked up a weak weather mutation just before you wanted a high-value one. This behaviour is community-reported.