Rust Grow Calculator

How Rust grow times are calculated

Grow time in Rust depends on four things: the plant's gene string, its current light level, water saturation and ambient temperature. The Grow Calculator combines all four to give you exact times in minutes for each stage transition — so you know precisely when to clone, harvest or replant.

Rust plant stages

Every Rust crop moves through a series of growth stages. The calculator above shows how long each stage takes for your exact genes and conditions, so you know when to clone and when to harvest:

• Seedling — just planted; no harvest yet.
• Sapling — visible growth begins.
• Sprawling — pre-crossbreed stage.
• Crossbreed — clone window. Genetics finalise here.
• Ripe — harvest stage. Yield is full.
• Dying — past prime; harvest gives reduced output.

How genes and conditions affect time

More G genes reduce grow time on a diminishing curve — roughly 17% off at 1G, 33% at 2G, 47% at 3G, scaling further to ~64% off at 6G. Each Y gene increases yield but doesn't speed up growth. Each H gene reduces the penalty when conditions dip below 100%. Conditions matter most when they're not at 100% — a plant in poor conditions grows noticeably slower than the same plant in ideal conditions.

Best conditions

Run electric ceiling lights and a sprinkler-fed planter and your plants will run at 100% conditions 24/7. If you can't afford the power, glow plants alone keep light at ~70% — usable but slower. The calculator above lets you simulate different setups so you can see exactly how much time you save by upgrading.

Why a god clone matters more than upgrading lights

A GGGYYY clone with average conditions still beats a plain GYWXGY clone with perfect conditions. If you only have time for one optimisation, breed god clones first. Use the God Clone Planner to find your shortest route to GGGYYY, then come back here to time your harvests.