Grow boosters shorten the remaining time of currently running production batches. They are one-use items rather than permanent production-speed upgrades.
| Item | Time removed from each running batch | Booster cooldown added |
|---|---|---|
| Grower's Fertilizer | 1 hour | 3 hours |
| Hothouse Formula | 3 hours | 6 hours |
| Master Grower's Kit | 6 hours | 10 hours |
The effect applies to every currently running production batch, including batches in other cities. A batch with less time remaining becomes ready immediately; unused relief does not carry into a future batch.
Already-ready batches are unaffected. The effect does not accelerate processing jobs, collect output, create a new batch or permanently increase yield. If no production batches are running, the use is rejected without spending the item.
All booster-group items share an accumulating cooldown budget. A use is allowed while the current remaining budget is below 24 hours. The full item's cooldown charge is then added, even if the new total exceeds 24 hours.
For example, using Grower's Fertilizer with 23 hours remaining produces a 26-hour budget. Another booster use is blocked until the remaining budget falls below 24 hours. This budget is separate from drug and medical cooldowns.
Start the batches you intend to accelerate before using the booster. Compare their remaining times: a six-hour reduction has little extra value over a one-hour reduction if all batches are already within an hour of finishing.
Use one item through its Inventory action, then check the revised completion times. Collection still carries the ordinary collection rules and bust risk.
Game-item effects checked against executable code and current item migrations on 17 September 2026.