Plague upgrades in Unharvest dictate how quickly you can corrupt and wither overgrown wheat fields in SkorpionDev's reverse-farming incremental game. Pressing Tab opens the progression menu, where you spend collected skull currency—earned from each withered stalk—to upgrade passive infections, summon biological swarms, and automate field clearing.
Below are all confirmed upgrade branches, verified resource costs, and mechanics observed across the playable demo and official Steam announcements.
Direct Withering and Tool Upgrades
Direct withering forms the foundation of your resource generation during early runs. Interacting with crops using left-click harvests plant life and deposits skulls directly into your balance in the top left corner of the screen.
| Upgrade Name | Cost (Skulls) | Primary Effect |
|---|---|---|
| Stalks Per Wither I–V | 25, 50, 300, 5,000 | Increases crop yield per click from 1 to 2, 3, 5, 8, and finally 20 stalks |
| Wither Cooldown Reduction | 20, 50, 100, 250, 25,000, 100,000 | Lowers click recovery time through tiers (3.0s down to 0.7s, 0.4s, and 0s) |
| Hold to Wither | 1,000 | Removes the need for individual clicks by sustaining decay while holding left-click |
| Critical Wither Chance | 100, 1,000, 4,000, 20,000 | Adds a percentage chance (scaling from 5% to 20%) to trigger a critical harvest |
| Critical Wither Reward | 750, 5,000, 15,000 | Adds bonus skull payouts (+1, +5, +10, +20) on critical strike activations |
Purchasing the final 100,000 skull Wither Cooldown tier sets recovery time to zero seconds, converting direct clicks into instantaneous clearing.
Spore Infection Abilities
Unlocking spores introduces procedural spread mechanics across dense crop clusters. Once unlocked for 100 skulls, each manual wither event gains a probability to trigger a chain reaction that wilts neighboring stalks without extra player inputs.
- Unlock Spores: Costs 100 skulls. Unlocks passive fungal contagion across nearby stalks.
- Spread Chance: Scales from an initial 10% base rate to 25%, 40%, and caps at 50% for high-tier upgrades (costing up to 10,000 skulls). At the maximum tier, every second decay action triggers an area spread.
- Spread Radius: Expands the infection boundary from 1 meter to 3 meters, 6 meters, 10 meters, and 15 meters. Higher tiers require investments ranging between 250 and 20,000 skulls.
- Auto Wither (Wither as You Walk): Costs 20,000 skulls. Projects an automated aura around your character model, instantly destroying any stalks you walk across.
Locust Swarm Upgrades
The Locust Swarm functions as an active biological strike weapon aimed by pointing your cursor and holding right-click. Unlocking the swarm costs 10,000 skulls and deposits a massive cloud of insects that moves across the field, wiping out dense patches of wheat along its path.
| Swarm Upgrade | Stat Increase | Typical Costs |
|---|---|---|
| Swarm Cooldown | Drops cooldown from 60 seconds down to 45s, 35s, and 30s | 2,000 to 35,000 skulls |
| Swarm Duration | Extends flight activity from 6 seconds to 12s, 18s, and 25s | 2,500 to 35,000 skulls |
| Swarm Radius | Expands impact width from 5 meters up to 12m, 20m, and 25m | 2,500 to 41,000 skulls |
| Swarm Speed | Accelerates swarm transit velocity from 8ms to 15ms | 2,500 to 17,000 skulls |
Releasing swarms from field perimeters towards the central barn or windmill maximizes total clear coverage before insects exhaust their active flight timer.
Locked Abilities for Full Release
The demo interface previews several skill nodes that remain inaccessible until the planned release on December 7, 2026. Players attempting to buy these nodes encounter a full game restriction message:
- Unlock Blight: Placed at the end of the spore progression path.
- Unlock Rot: Displayed alongside intermediate contagion modifiers.
- Unlock Rats: A rodent-based active pest category positioned alongside insect abilities.
- Swarm Count +1: An upgrade node intended to allow multiple concurrent swarms across larger environments.
Frequently Asked Questions
What is the fastest path to automate harvesting in Unharvest?
Hold to Wither costs 1,000 skulls and removes click spamming. Saving 20,000 skulls for Wither as You Walk fully automates movement clearing, allowing you to walk through stalks without pressing any attack inputs.
What is the maximum upgrade for Wither Cooldown?
The maximum Wither Cooldown upgrade costs 100,000 skulls and reduces cooldown time to 0 seconds, making direct withering instantaneous.
Can you unlock rats or blight in the Unharvest demo?
No. The demo interface explicitly flags Blight, Rot, Rats, and Swarm Count nodes as features reserved for the full commercial release.
