Composters and fertilizer (the horticulture multiplier)

The composter is the single most important deployable in any serious Rust farm. It turns leftover plant matter, mushrooms, berries, and even human waste into fertilizer, the consumable that accelerates planter growth, boosts yields, and effectively doubles the throughput of any greenhouse setup. If you are running clones for max-genetic crops, you are running composters — there is no alternative path to industrial-scale farming in Rust 2026.

This page is the definitive composter reference: craft cost, every compostable input with its exact fertilizer yield, the math behind why fertilizer matters, the human-waste loop, Industrial Crafter integration, and the closed-loop workflow that keeps a greenhouse self-sustaining.

1. Crafting the composter

The composter is a deployable workbench-tier-1 item that sits on any foundation or large floor square. It does not require power, water, or any external input — it just needs material dropped into its inventory.

Placing and positioning the composter

Deployment is deliberately forgiving. The composter snaps to any foundation tile, ceiling tile, or large floor square and needs roughly one full tile of clearance — it will refuse to place inside a doorway or where it clips a wall. Because it draws no electricity, water, or fuel, you are free to tuck it into a dead corner that has no other use: the corner of a 2x2, the spare square beside a furnace bank, or directly between two planter rows. The only placement rule worth remembering is the decay rule — anything with a roof tile overhead counts as "inside" and decays at zero, while an open-air composter loses condition over roughly eight hours and will eventually collapse if you forget it. Lay one cheap twig roof above it and the problem disappears permanently.

To craft it you first unlock the blueprint, then build it at any Workbench Level 1. The raw-material cost is intentionally tiny so that even a fresh-spawn solo can afford it within the first hour:

• Unlock — 75 scrap at a Research Table (drop a found composter in and research it) or 75 scrap down the WB1 tech-tree branch. You never need both.
• Craft — 200 wood, 30 metal fragments, and 1 gear at a WB1. The gear is the only component you cannot strike off a tree or rock; one road-side or supermarket barrel run yields several.
• Craft time — a few seconds; it is not a gated long-craft item.

That total — 75 scrap plus pocket-change resources — is the entire barrier to a permanent, free fertilizer supply for the rest of the wipe. It is one of the highest return-on-investment deployables in the game, which is why experienced players treat it as a day-one priority alongside a furnace and a sleeping bag.

Pick it up with a hammer — no building privilege needed if you own it, but standard TC rules apply for placement. A single Gear is the only "premium" component; everything else is trivial salvage from any roadside barrel run. Most players unlock composters within their first hour on a fresh wipe because the scrap cost is so low and the payoff is so high. [rustlabs] [rust.fandom]

2. Compostable inputs — full table

Every input is consumed individually (one item = one composting tick). Fertilizer accrues in a hidden internal buffer; once the buffer reaches 1.0, one fertilizer item is produced and pushed into the output slots. Values below are the fertilizer-per-item yields confirmed against rustlabs item data and the current Facepunch farming pass.

Cloth-yielding plants in Rust are hemp, corn (foliage), pumpkin (foliage), and berries (all colors). Of these, only hemp produces an explicit "residue" item (hemp fiber from harvesting); the others are composted as the whole fruit or seed. Cloth itself is not compostable — only the plant matter is. [rustlabs] [corrosionhour]

3. Human Waste — the renewable input

Every player drops Human Poop on a randomized timer driven by food and water intake. Eat and drink normally, and you will produce roughly 1 poop every 15–25 in-game minutes, dropping it directly into your inventory with a notification.

• Yield: 3 fertilizer per poop, composted in the same slot as plants.
• Renewable: infinite as long as you eat and drink.
• Slow: a solo player produces ~3–4 poops per hour, so this is a trickle, not a torrent.
• Group multiplier: a 5-man base eating together produces ~15–20 poops/hour, which is meaningful — that is 45–60 fertilizer/hour from waste alone.

Horse Dung works identically (3 fertilizer) and accumulates wherever a horse is stabled. If you keep horses in a hitching post next to the composter, that is another passive 2–3 fertilizer/hour per horse. [rust.fandom] [rusttips]

4. Fertilizer math — what 1 fertilizer actually does

A single fertilizer item, when consumed by a planter, applies one growth tick to the plant currently growing in that planter slot. The effect is not a flat percentage of total growth time — it is a fixed time skip.

In practical terms, a hemp plant with 6Y genetics + Pure Yield Tea + fully fertilized produces roughly 3.5–4x the cloth of an unfertilized, ungenetic plant. That is why fertilizer matters: it is the multiplier that turns a hobby farm into a cloth printer. [rustlabs] [corrosionhour]

For growth speed specifically: a fertilizer-saturated 6G (Growth) plant on a sprinkler-watered planter goes from sapling to ripe in ~30 minutes instead of the unfertilized ~75–90 minutes. That is the loop that makes greenhouses lucrative. [rusttips]

How fertilizer is actually applied to a plant

Fertilizer is not crafted into anything and it is not eaten by the player — it is storage that the planter consumes automatically. Open any Planter Box or Large Planter Box and you will see a small inventory grid attached to the soil; this is the fertilizer reserve. Drag fertilizer stacks into that grid and the planter does the rest. On every internal growth tick the planter checks its reserve, and if fertilizer is present it silently spends one unit to accelerate the plants growing in that soil and to raise the eventual harvest yield. You never click a plant to "use" fertilizer — you simply keep the planter's reserve topped up and the game feeds it for you. A Large Planter Box holds a generous fertilizer buffer, so a single top-up can carry a crop through an entire grow cycle untouched.

The headline figure repeated across community guides and Facepunch's farming notes is that a well-stocked fertilizer reserve speeds a crop along by up to roughly 30% compared with growing the same genetics in unfertilized soil — the same crop simply reaches harvest noticeably sooner, and it does so while also paying out a larger fruit count. Two effects are bundled into that one number: a per-tick time skip that compresses the grow timeline, and a per-tick yield bonus that pushes the final harvest toward the plant's fruit cap. The practical reading is simple — an empty fertilizer slot is wasted growth, so the discipline is never to let a planter run dry.

5. Mass-fertilizer mode — Industrial Crafter pipeline

Since the Industrial update, composters can be wired into the Industrial Crafter / Conveyor system via the /24 (or /1, /6) item-filter syntax.

• Conveyor IN: pull compostables (berries, corn, mushrooms) from a storage box on a filter — e.g. Mushroom /24 pulls mushrooms in stacks of 24 per cycle.
• Conveyor OUT: push fertilizer from the composter's output into a planter-feeding conveyor, again filtered (Fertilizer /1 to drip-feed planters one at a time).
• Stack auto-management: setting the filter to /24 (or any number ≤ the stack size) lets you balance the composter's 6 input slots without micromanagement.

A typical "fert factory" layout: one large storage box of bulk berries/mushrooms → conveyor → composter → conveyor → distribution box that fans fertilizer out to each planter row via filtered conveyors. Once built, the loop runs hands-off until input runs dry. [rustlabs] [Facepunch patch notes]

6. Greenhouse + composter co-location

The greenhouse building skin (glass roof + walls) provides a +25% plant temperature bonus and +12% light bonus during nights and overcast weather. Composters slot naturally into greenhouse builds because:

• Planters need fertilizer — there is no point growing 6/6/6 genetics if you do not feed them.
• Clones do not drop seeds — a cloned cutting harvested as a plant gives no seed return, so you cannot replant from the harvest. You must either keep one "mother plant" producing seeds, or compost the surplus harvest and accept the closed loop is fertilizer-out, not seed-out.
• Cloned cuttings retain parent genetics exactly. The standard meta is: hand-cross to 6/6/6 genetics → take cuttings → fill every planter with identical 6/6/6 clones → fertilize aggressively → harvest → compost ~20% of harvest → repeat.

Placing the composter inside the greenhouse keeps decay at zero and shortens the walk from harvest to compost to planter. A 6-planter greenhouse with one composter and one mixing table for tea is the canonical layout. [rust.fandom] [corrosionhour]

7. What CAN'T be composted

The composter is plant-and-waste only. The following items cannot be inserted, even though new players try every wipe:

• Raw meat (any kind) — spoils into Spoiled Meat, which also cannot be composted
• Cooked meat — useless to the composter
• Animal fat — crafting input only
• Chicken / Bear / Boar / Wolf meat — none compost
• Eggs (where available on modded/community servers) — do not compost
• Fish (raw or cooked)
• Cloth — the processed material does not compost; only the source plant matter does
• Low Grade Fuel, Charcoal, Wood — not organic in the composter's logic

If it came from an animal carcass or a workbench, it is not compostable. Stick to whole fruits, seeds, mushrooms, berries, and waste. [rustlabs] [rusttips]

8. Closed-loop workflow

The canonical Rust 2026 farming loop:

1. Harvest ripe plants from your greenhouse planters (right-click → Harvest, or use a Garden Tool for genetic readout).
2. Triage the harvest: keep ~70–80% for cloth/food/scrap, dedicate ~20–30% to composting.
3. Seed the composter: drop berries, corn, pumpkins, and surplus seeds into the 6 input slots.
4. Collect fertilizer: pull stacks from the output as they fill (or wire via Industrial Conveyor).
5. Feed planters: right-click fertilizer onto each planter, or drop into the planter's inventory directly. Each fertilizer applies instantly.
6. Repeat: cloned cuttings replace harvested plants in <10 seconds, and the planter is back to growing on accelerated time.

The loop is genuinely closed for fertilizer. It is not closed for seeds — you need at least one mother-plant slot growing from seed to keep cuttings flowing. Most players dedicate 1 of 6 planters per crop to a seed-mother. [corrosionhour] [rusttips]

Why the closed loop is the whole point

The reason farmers obsess over the composter is that it converts a recurring cost into a recurring asset. In an unfertilized farm every grow cycle is just a slow trickle of cloth or food. In a composted greenhouse, the waste products of one harvest become the accelerant for the next: the 20–30% of fruit you would otherwise discard, every surplus seed, the plant fiber left over after picking, the human poop you generate just by eating, and the dung from a stabled horse all flow back into the composter and emerge as fertilizer. That fertilizer then makes the following crop grow faster and yield more — which produces even more surplus to compost. The loop is genuinely self-funding: after the one-time 75-scrap unlock, the farm never costs another resource to keep running at peak speed.

Is fertilizer worth it? — the economy

For anyone weighing the effort, the answer is an emphatic yes, and the maths is not close. The inputs are effectively free: mushrooms litter every forest, berries and surplus seeds pile up from your own crossbreeding, and human waste accrues whether you want it or not. Against that zero cost, fertilizer delivers a compounding return — up to ~30% faster cycles means more harvests per wipe, and the stacking yield bonus means each of those harvests is fatter. For a cloth farmer that is the difference between a hobby plot and an industrial printer; for a food farmer it is steady calories with no scrap sink. The only "cost" is the walk from harvest to composter to planter, and the Industrial Conveyor pipeline in section 5 removes even that. There is no realistic scenario in which running a composter is not worth it.

Common mistakes

• Leaving the composter outdoors. The eight-hour decay timer quietly destroys uncovered composters while you are off raiding. Always roof it.
• Trying to compost meat, fish, cloth, or fuel. The composter is plant-and-waste only — see section 7. New players burn minutes wondering why raw meat will not insert.
• Letting the planter's fertilizer reserve run dry. An empty reserve means the crop reverts to the slow unfertilized rate — you lose the ~30% speed-up for free. Top up on every visit.
• Composting your only seeds. Surplus seeds are great compost, but never feed in the seeds you still need to replant — cloned harvests return no seed, so you must keep a seed-mother running.
• Hoarding horse dung in a box. Dung is your single best input at 5 fertilizer each — get it into the composter rather than letting it occupy storage.
• Building one composter for a giant farm. One composter comfortably feeds about six planters; scale composters up alongside planter count.

Pro tips for an optimal pipeline

• Stable a horse next to the composter. A single idle horse drips out dung passively, and at 5 fertilizer per dung it is the highest-value input in the game for zero ongoing effort.
• Front-load mushrooms on fresh wipe. While your real crops are still saplings, a five-minute forest roam banks hundreds of fertilizer's worth of mushrooms — your farm hits the ground fertilized.
• Pre-fill planter reserves before logging off. A Large Planter Box's fertilizer buffer can carry a crop through an entire offline cycle, so you wake up to a finished, accelerated harvest.
• Co-locate everything. Composter, planters, mixing table, and horse stable inside one greenhouse shell collapses the whole loop into a few steps and keeps every deployable at zero decay.
• Wire it once, forget it. An Industrial Conveyor feeding compostables in and fertilizer out turns the loop fully hands-off — see section 5.

9. Pro tips

• Mushroom forests are composter gold. A 5-minute roam through any forest biome yields 30–60 mushrooms; that is 150–300 fertilizer per trip with zero farming infrastructure. New wipes especially: mushroom-compost while your real farm is still growing.
• Berries are the most efficient input per slot. 5 fertilizer per item and they stack to 10 per slot means a single composter slot holds 50 fertilizer's worth of input. Corn/pumpkin yield more per item but stack to only 1 (whole) or 6 (cut), so berries win on slot-density.
• Human waste is renewable but slow. Do not rely on it as a primary input — treat it as the background trickle that pays for itself.
• Surplus seeds compost for 2 each. Once you have a stable 6/6/6 cutting pipeline, every raw seed in your inventory is composter food.
• Decay matters outside. Always place composters indoors or under a roof — 8-hour outside decay will eat your investment if you go raiding.
• One composter feeds ~6 planters comfortably. Scale composters 1:6 with planters as a rule of thumb.

10. Sources

1. rustlabs.com — Composter item page, fertilizer yields, craft cost
2. rust.fandom.com — Composter wiki entry, Human Poop mechanics
3. corrosionhour.com — Rust farming guide, genetic + fertilizer math
4. rusttips.com — Compost loop walkthrough, mushroom strategy
5. Facepunch patch notes — Industrial update conveyor filter syntax, farming 2.0 fertilizer rebalance
6. rustlabs.com — Industrial Crafter / Conveyor item-filter documentation

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