Gooey Mulch is an item in the “Mulch” category (Items). It costs ₽200.
In-game descriptions
| Diamond / Pearl · Platinum | A plant fertilizer spread on soft soil. It ups the number of times new plants grow where mature plants withered. |
|---|---|
| HeartGold / SoulSilver | A fertilizer to be spread on soft soil. It ups the number of times new plants grow where mature plants withered. |
| Black / White · Black 2 / White 2 | A fertilizer to be spread on soft soil in regions where Berries are grown. A maniac will buy it for a high price. |
| X / Y | A fertilizer to be spread on soft soil in regions where Berries are grown. |
| Sun / Moon · Ultra Sun / Ultra Moon · Let’s Go, Pikachu! / Let’s Go, Eevee! · Sword / Shield | A fertilizer for growing Berries. However, it appears to be unsuitable for the soil in the Hoenn region and has no effect. |
Where to find it
Not placed on the atlas maps (so far: Red/Blue and Generation 3).
Sources : PokeAPI (items, item_flavor_text, machines) · atlas · pokeemerald species_info.h