Quick answer: Unlock the Planter Box for 2,000 Gold, wet Seeds before they reach it, and leave open collection space underneath. A Wet Seed touching the box grows into a Flower; destroying the Flower releases 1 Gold and 4 Amethelis, and those are the only solid outputs that can pass through the Planter Box.
The complete Planter Box chain
The current official pages describe this production chain:
Seed + Water → Wet Seed → Planter Box → Flower → 1 Gold + 4 Amethelis
The Planter Box is not a container that you fill through a menu. It reacts to a physical Wet Seed that touches the building. The Flower then occupies space above the box until you destroy it with a weapon or Fire.
The official Research table currently lists the Planter Box at 2,000 Gold. Sandustry is in Early Access and that table is marked WIP, so recheck the in-game cost after a major patch.
Prepare the input and output first
Build the line around three distinct spaces:
| Area | Material | Required condition |
|---|---|---|
| Upper input | Wet Seeds | A small, controlled feed that reaches the top of the box |
| Growth area | Flower | Open vertical and side space so the plant is visible and reachable |
| Lower catch | Gold and Amethelis | Empty space below the box for both solid outputs to pass through |
Make Wet Seeds away from the planter when possible. The Water Guide explains the current Seed + Water reaction and how to contain the liquid. A large uncontrolled Water stream can interfere with nearby transport long before it improves Flower production.
Build a reliable first planter
- Excavate the lower collection chamber. Do this before placing the box. Gold and Amethelis can pass through the Planter Box, but a full chamber leaves them nowhere useful to go.
- Place one Planter Box. Keep the top and the growing area exposed while testing. Do not bury the machine inside a completed factory module.
- Prepare one Wet Seed. Let a Seed absorb Water in a contained mixing point, then move the result toward the planter.
- Feed from above in a small batch. Confirm that a Wet Seed actually touches the box and becomes a Flower before releasing more material.
- Harvest the Flower. Destroy it with a weapon or Fire only after the output area is ready.
- Watch both outputs fall through. The official Planter Box page says Gold and Amethelis are the only solid pixels that can pass through it.
- Add transport after the complete cycle works. Use the Automation Guide to move collected solids away without blocking the lower chamber.
The first test should prove one complete Seed-to-output cycle. Scaling before that point only creates a larger pile around the same unknown failure.
Troubleshoot Planter Box problems
A Seed touches the box but nothing grows
Check the material name with the Grabber. A normal Seed is not the required input; the official mechanic requires a Wet Seed. Move the wetting step upstream and confirm Water actually contacts the Seed.
Wet Seeds stop before reaching the box
Close the upstream feed and inspect the final drop. A narrow corner or an existing Flower can keep the next Wet Seed from touching the building. Clear the last step first instead of increasing conveyor speed.
A Flower grows but no resources appear
Growth is not the harvest step. The official Flower page says the plant must be destroyed by a weapon or Fire to drop its Gold and Amethelis.
Gold or Amethelis will not leave cleanly
Inspect below the Planter Box. The output chamber may be full, too narrow, or connected to a blocked route. Amethelis is a Wisp material that drifts side to side while falling, so give the collection area more width than a single straight shaft.
The planter works once, then stops
Trace the line backward: lower output, Flower harvest, Wet Seed contact, then Water and Seed supply. Do not add more boxes until the first failed stage is clear.
Where this fits in progression
The early Processing Plant Guide produces Gold through Wet Sand and the Shaker. The Planter Box is a later, separate botanical production method. Its Amethelis output also feeds deeper resource chains, while Gold continues to fund Research.
After the plant line is stable, the Flux Emanator Guide explains a later Voidbloom-to-Fluxite process. Keep these as separate modules: the Planter Box makes Flower outputs, while the Flux Emanator requires Voidbloom.
Verified sources
Facts on this page were checked on August 17, 2026 against:
- Official Planter Box page
- Official Flower page
- Official Amethelis page
- Official Water page
- Official Research table
The Research table is marked WIP. Recheck costs and interactions after major Early Access updates.