Mutations are the single biggest multiplier on a crop in Build A Ring Farm, so the question of which is best comes up constantly. The short answer: Fire (10×) sits highest on paper, but “best” depends on what you can actually get and afford. This guide compares the top mutations head-to-head. For where mutations fit into your income, see how to make money fast; for how the events that trigger them work, see how weather events work.
All multipliers here are community-reported and cross-checked across guide sites. The Update 4 mutations (Cosmic, Fire) in particular are contested between sources, so treat the exact numbers as strong leads and verify in-game.
The full multiplier ladder
Here’s how the top mutations stack up, based on Pro Game Guides and other sources:
- Fire — 10× (Update 4, spray-only, contested)
- Cosmic — 8× (Update 4, spray-only, very expensive)
- Honeycomb — 6.5× (Queen Bee event, ~0.5%)
- Rainbow — 5× (Galaxy event ~1%, or Rainbow Spray)
- Farm — 4×, Alien — 3.25×, Radioactive — 3× (mid-tier event mutations)
The jump from Rainbow (5×) to Fire (10×) doubles a harvest’s mutation bonus — but as you’ll see, the highest multipliers are also the hardest and most expensive to apply.
Rainbow — the reliable workhorse
Rainbow (5×) is the mutation most players actually build around. It appears during the Galaxy event at roughly a 1% chance, and crucially it can also be bought as a Rainbow Spray from the Gear Shop — so you don’t have to wait for the right event to land it on your best crop. That accessibility is what makes Rainbow the practical champion: a guaranteed 5× you can apply on demand often beats a higher multiplier you can rarely trigger. For most farms, Rainbow is the workhorse mutation.
Honeycomb — the rare event king
Honeycomb (6.5×) is the strongest pre-Update-4 event mutation, but it only comes from the Queen Bee event at a brutal ~0.5% chance and has no spray. That makes it more of an opportunistic bonus than something you can plan around — when a Queen Bee event hits, you want your highest-value crops fully grown and ready to catch it. Reliable it is not, but landing Honeycomb on a Dragonfruit is a genuinely huge harvest.
Cosmic — the premium spray
Cosmic (8×) is an Update 4, spray-only mutation, and it’s expensive — reports put the Cosmic Spray at around 25T cash plus 25,000 Plant Tokens. It’s a clear upgrade over Rainbow’s 5×, but the cost means you should reserve it strictly for your very best crops on the Outer ring. Spraying Cosmic on anything but a top-tier seed is a waste of a serious investment.
Fire — the new ceiling
Fire (10×) is the highest reported multiplier in the game after Update 4. Like Cosmic it’s spray-only and pricey, and its exact value is the most contested figure of the bunch — some sources list it differently, so confirm in-game before treating 10× as gospel. If the number holds, Fire is the new top of the ladder, best saved for a single showcase crop where a 10× multiplier on the Outer ring produces the largest single harvest possible.
So which mutation is best?
It depends on your goal:
- Best practical mutation: Rainbow. Accessible via event and spray, a guaranteed 5× on demand. This is what most farms run.
- Best multiplier you can plan for: Cosmic. If you can afford the spray, an 8× on your best crop is worth it.
- Highest possible: Fire (10×), for a single showcase harvest — if the reported value holds up.
- Best free bonus: Honeycomb, when the Queen Bee event happens to hit your ready crops.
How to use mutations well
Whatever you land, the rules are the same: a plant carries only one mutation at a time, so never overwrite a good one cheaply, and always apply your best mutations to your highest base-income crops on the Outer ring. The biggest harvest in the game is a Dragonfruit or Ghost Pepper, on the Outer ring (19×), wearing Rainbow, Cosmic or Fire. Use the Acid Spray to clear a bad mutation if you need to reset, and check the full mutations table and best mutations ranking for every value. Then run your planned combo through the calculator to see exactly what it earns before you spend a single expensive spray.