As in pokemon, all you need to evolve a Gloom is to give it a leaf stone
In order to get a vileplume evolve your gloom with a leaf stone. If you want a bellosom evolve it with a sun stone.
All you need is a Leaf stone. Use it on Gloom and it will evolve into Vileplume.
Gloom evolves into Vileploom with a Leaf stone To get gloom to evolve into a Bellossome, you need to use a Sun stone I suggest you catch two oddishs in order to get both Vileploom and Bellossome into your Pokedex.
In SoulSilver, Oddish will evolve into Gloom at Level 21 however Gloom can evolve 2 different ways, you can use a Leaf Stone on it in order for it to evolve into Vileplume or you can use a Sun Stone on it in order for it to evolve into Bellossom.
There are two ways to evolve a Gloom, you can either evolve it into Vileplume or you can evolve it into Bellossom. To get Vileplume all you need to do is use a leaf stone on it. Likewise to get Bellossom you have to use a stone on Gloom, but this time it is a Sun Stone.
Unfortunately, Gloom is one of those Pokémon that does not evolve by level. If you want Gloom to evolve into Vileplume, you will need to find a Leaf Stone. If you want to make it evolve into Bellossom (which appeared in the second generation (Gold/Silver)) you will need to find a Sun Stone. Also, this is not specific to FireRed, evolution factors are the same through all the different games (though certain pokemon, like Tangela, can only evolve in later versions of the series). For more information, try this site: http://www.serebii.net/pokedex-dp/044.shtml
all you need to do is get a oddish evolve it into gloom and us a sunstone on it and it will evolve into belloseum!
Use a Sun Stone on Gloom to evolve it into Bellossom
You can evolve gloom to bellossom usig the sun stone.
gloom can evolve into bellosom and sunkern can evolve into sunfloria.
No, Gloom does not evolve with the use of a Moon Stone, Gloom evolves with a Leaf Stone and once you use it then it will evolve into Vileplume or you can opt to use a Sun Stone and it will cause Gloom to evolve into Bellossom.
Use a leaf stone on your Gloom. Ta-da! You now have Vileplume! OR use a Sun-Stone on it. Ta-da! BELLOSSOM!!!! To evolve it into a Vileplume, use a Leaf Stone. To evolve it into a Bellossom, use a Sun Stone.