It is not possible to catch a Sunkern in Pokemon LeafGreen version. The only way to get one is to trade for it.
TRADE FROM EMERALD
Gloom and Sunkern.
sunkern to sunflora (trade from emerald) gloom to bellossom
national park and if you want to enovle him win a sunstone in the bug catching contest
tangela sunkern sunflora roseila cacnea cacturne lileep cradily there might be more but i don't think so :) happy Pokemon playing :)
Sunkern is a Grass type pokemon.
Sunkern, the Seed Pokemon evolves into Sunflora, the Sun Pokemon. Both Pokemon are plant type pokemon.
SUNKErn SUNKErn SUNKErn
You can find sunkern in national park
A sunstone evolves an Eevee into an Espion in Pokemon gold and silver. this will not work in firered/leafgreen. It could also be done in ruby/sapphire/emerald though I'm not sure.
sunkern or gloom sunkern into sunflora and gloom into bellosom
Sunkern evolves into a sunflora when a sunstone is used on it.