Unfortunately, anonymous, bayleef’s signature aroma comes from its leaves and thus can only be influenced by location and temperature at the time of their growth. However, it’s possible to slightly alter the biochemistry (and thus odor) of bayleef’s main body simply by changing its diet. Strong-tasting, pungent foods, such as those that contain tamato berries or garlic, are particularly recommended for this purpose, but be warned that this may result in an unappealing smell for you, as the smell from bayleef’s leaves may intermingle with its body. Additionally, these changes tend to be temporary unless you’re consistent with what you feed bayleef.
I wish you godspeed, anonymous.