It evolves at level 30 the last person was so wrong! Actually, gloom evolves with a leaf stone or a sun stone.
Done by: *******
sun stone
Use a Sun Stone on Gloom to evolve it into Bellossom
It evolves into Gloom starting at Level 21
with a sunstone get one underground
As of Pokémon Pearl, there are only two Pokémon that can evolve with the Sun Stone item, the first Pokémon that can evolve with it is Gloom and it will evolve into Bellossom and the second Pokémon that it will evolve is Sunkern and it will evolve it into Sunflora.
Personally i would say as soon as you get gloom evolve it.
any level you want to evolve it att
it doesnt
gloom to bellosom sunkurn to sunflora Sunkern and Gloom are the ones who evolve using a Sun Stone.
gloom
you have to use a leaf stone on gloom or you can get a bellosom with a sunstone used on gloom.
You can evolve Sunkern or Gloom with a sun stone. Gloom to Bellossom. Sunkern to Sunflora.