How to Evolve Gloom

To evolve Gloom, you must use a specific evolution stone directly from your bag. Use a Leaf Stone on Gloom to evolve it into the Grass/Poison-type Vileplume. Alternatively, use a Sun Stone on Gloom to evolve it into the pure Grass-type Bellossom. There is no level requirement for either evolution.

Gloom features a split evolutionary line that depends entirely on the item you expose it to. You do not need to reach a specific level or trade the Pokémon. The choice between the two final forms dictates your future movepool and typing.

Here is the exact mapping for Gloom's evolutions:

• Vileplume: Requires a Leaf Stone. Retains the Grass/Poison dual typing.
• Bellossom: Requires a Sun Stone. Becomes a pure Grass-type.

Using the stone consumes it permanently. Once you confirm the evolution, you cannot reverse the process. Players often debate when to trigger the evolution, as Gloom learns moves like Petal Blizzard at level 44, which its evolved forms cannot learn naturally.

However, modern move reminder systems and Technical Machines (TMs) make early evolution much safer. Evolving Gloom immediately after it evolves from Oddish at level 21 provides a massive stat boost that trivializes early-game story battles.

In Pokémon Legends: Z-A, the evolution process remains seamless and tied to the overworld inventory system. You do not need to visit a specific facility to trigger the transformation. The mechanics mirror the previous Legends title, focusing on direct item application.

Follow these exact steps to evolve Gloom in Lumiose City:

1. Open your main satchel using the D-pad.
2. Navigate to the Everyday Items tab where evolution stones are stored.
3. Select either the Leaf Stone or Sun Stone and press Use.
4. Select Gloom from your active party to initiate the evolution sequence.

Finding the required stones requires engaging with the city's economy. You can purchase both the Leaf Stone and Sun Stone at the central Trading Post using Merit Points (MP). Merit Points are earned by recovering lost satchels across the urban map.

Alternatively, stones occasionally drop from space-time distortions or specific urban anomalies. If you want to evolve Gloom early in your playthrough, farming MP is the most deterministic method to secure the exact stone you need.

In Pokémon Scarlet and Violet, the evolution method remains identical, but acquiring the stones involves exploring the Paldea region. The game separates the availability of the two required stones, making one significantly easier to obtain than the other.

Here is how to execute the evolution in Paldea:

1. Open your Bag and scroll to the Other Items pocket (the candy icon).
2. Locate your Leaf Stone or Sun Stone.
3. Select the stone, choose Use this item, and select Gloom.

Acquiring a Leaf Stone is incredibly straightforward. Once you defeat three Gym Leaders, every Delibird Presents store in Mesagoza, Levincia, and Cascarrafa will stock Leaf Stones. They cost 3,000 Pokédollars each, allowing you to buy as many as you need.

The Sun Stone requires more effort, as it cannot be purchased in shops. You receive one guaranteed Sun Stone as a reward for completing the Artazon Gym test (the Sunflora Hide-and-Seek mini-game). If you need more, you must scour the Asado Desert for sparkling hidden items on the ground, which have a low percentage chance to yield a Sun Stone.

The mobile mechanics in Pokémon GO deviate from the mainline games by introducing candy requirements alongside the evolutionary items. Evolving Gloom here is a test of resource management rather than simple item application.

The requirements differ drastically between the two forms:

• Vileplume: Costs exactly 100 Oddish Candy. No stone is required.
• Bellossom: Costs 100 Oddish Candy AND one Sun Stone.

Farming Oddish Candy requires catching multiple Oddish or Gloom. Use Pinap Berries during every encounter to double the candy yield. Oddish frequently spawns during sunny or clear weather due to the weather boost system.

Acquiring the Sun Stone is the primary bottleneck for Bellossom. Sun Stones drop randomly from spinning PokéStops and Gyms, but the drop rate is less than 1%. Your best strategy is to complete your 7-day Field Research breakthrough or maintain a 7-day PokéStop spin streak, both of which guarantee a random evolutionary item.

Players occasionally hit roadblocks when trying to evolve Gloom. The mechanics are simple, but menu navigation errors or misunderstood mechanics cause the majority of these issues. Here are the most common blockers and their direct fixes.

Blocker 1: Giving the stone instead of using it.
This is the most frequent mistake. If you select Give from the menu, Gloom will simply hold the stone in battle. Evolution stones are consumable items, not hold items. You must select Use from the bag menu and apply it directly to the Pokémon.

Blocker 2: The Everstone trap.
If you received Gloom via a trade, check its summary screen. If it is holding an Everstone, it cannot evolve under any circumstances. Remove the Everstone and try using the evolutionary stone again.

Blocker 3: Leveling up with the stone.
Some players believe Gloom needs to level up while holding the stone. This is incorrect. The evolution triggers instantly in the menu the moment the stone is used, regardless of Gloom's current experience points or level.

Neither Vileplume nor Bellossom see usage in serious competitive formats. Their low base Speed stats and vulnerability to common offensive types keep them out of modern Smogon tiers. However, for a standard story playthrough, both offer distinct advantages depending on your team composition.

Vileplume (Rating: 7/10)
Vileplume is the superior choice for most story runs. The Grass/Poison typing provides crucial resistances to Fighting, Water, and Fairy attacks. With a base Special Attack of 111, it hits surprisingly hard with moves like Sludge Bomb and Giga Drain. If you secure the Chlorophyll ability and pair it with Sunny Day, Vileplume becomes a potent mid-game sweeper that outspeeds most NPC teams.

Bellossom (Rating: 6/10)
Bellossom drops the Poison typing, making it a pure Grass-type. Defensively, this is a downgrade, as it loses resistances to Fighting and Poison. Its main selling point is access to Quiver Dance, one of the best setup moves in the game. Unfortunately, setting up takes turns, which slows down the fast-paced nature of story battles. Choose Bellossom only if you specifically need a pure Grass attacker and are willing to invest turns into boosting its stats.