It’s easy to overlook fertilizer in Build A Ring Farm when you’re focused on seeds and mutations, but it solves one of the game’s real bottlenecks: grow time. The longer a crop takes to mature, the less often it pays out — and fertilizer fixes exactly that. This guide explains how fertilizer works, the differences between tiers, and when each is worth using. For the wider upgrade picture, see the upgrade order guide.
What fertilizer does
Fertilizer speeds up crop growth, shortening the time between planting and harvest. Since income depends on how often you harvest, faster growth directly increases your earnings — a crop that matures twice as fast effectively doubles its harvest cycles in the same period. This matters most for your slow, high-value seeds, where long grow times are the main thing holding back their value per second.
Normal, Strong and Super Fertilizer
Fertilizer comes in tiers that differ by how much they accelerate growth:
- Normal Fertilizer — a modest growth speed-up. Common and cheap, fine for everyday use on mid-tier crops.
- Strong Fertilizer — a larger boost. The UPDATE1 code grants three Strong Fertilizers, so you may have some already.
- Super Fertilizer — the largest growth acceleration. This is the one to save for your slowest, most valuable crops, where cutting the grow time has the biggest payoff.
The principle is the same as with sprays: match the strength of the resource to the value of the crop. A Super Fertilizer on a Carrot is wasted; on a Dragonfruit or Durian with a long grow time, it’s transformative.
Where to get fertilizer
Fertilizer comes from a few sources: the in-game shop, codes (UPDATE1 gives three Strong Fertilizers), and rewards from events and progression. According to community guides, composting harvests can also produce fertilizer — turning surplus crops into growth boosts — which makes it a renewable resource if you farm consistently. Keep an eye on code drops after updates, since fertilizer is a common code reward.
When to use each tier
- Normal Fertilizer: everyday use on Middle-ring crops to keep harvest cycles brisk.
- Strong Fertilizer: on your better Epic and Legendary crops, or to push a valuable crop to harvest just before a weather event so it’s ready to catch a mutation.
- Super Fertilizer: reserved for your slowest, highest-value Outer-ring crops — Exotic and Transcended seeds where the long grow time is the main limiter on income.
Timing is a hidden use here: fertilizing a crop to finish growing right as a Galaxy event hits lets it catch a Rainbow mutation it would otherwise miss.
Fertilizer vs the Sprinkler
Both speed up growth, so how do they differ? The Sprinkler is a permanent upgrade that improves growth across your whole farm continuously, while fertilizer is a consumable you apply to specific crops for a burst of acceleration. They stack: a well-upgraded Sprinkler handles your baseline speed, and you spend fertilizer to rush specific high-value crops or hit event timing. Prioritise the Sprinkler upgrade for steady gains (see the upgrade order guide), and treat fertilizer as the targeted top-up.
Fertilizer and event timing
One underrated use of fertilizer is hitting weather event windows. Mutations only land on fully-grown crops while you’re online, so if a valuable Galaxy event starts and your best crop is still growing, you’ll miss the Rainbow. A well-timed Strong or Super Fertilizer can rush that crop to maturity in time to catch the mutation — turning a missed window into one of your biggest harvests. Keep a couple of strong fertilizers in reserve specifically for this, rather than burning them all on routine growth.
Making fertilizer pay off
The biggest mistake with fertilizer is spreading it thin across cheap crops. Like sprays, it rewards focus: concentrate your strongest fertilizer on the crops where shaving grow time matters most — your slow, expensive Outer-ring seeds. Combine fast growth (fertilizer + Sprinkler), a high ring multiplier, a strong mutation and a maxed Saw, and a single crop can earn many times what it would unoptimised. Run the setup through the calculator to see how much faster harvest cycles translate into income, and tie it all together with the money farming strategy.