Scent is the best answer but fragrance does work with flowers, aroma is for describing food :)

The scent of wild flowers

All of them work, fragrance, aroma and scent

I'm going to offer a third view. I think both aroma and fragrance can work. I also think scent can work as well. This is really one of those areas where there is not a "correct" answer without actually getting into the subtle things you're trying to communicate -- or the mental imagery you are trying to create with your words. https://www.kemitron.com/the-difference-between-fragrance-scent-and-aroma/ might help a bit.

I disagree with the other two responses. Scent is inappropriate in the context as a scent is a distinctive smell. For example, a dog follows the scent of an individual person. Wildflowers is a word that could mean a mix of flowers. You could talk about "the scent of a pink rose," but a collection of flowers from a field would contain a mix of scents to create what you are smelling. It probably isn't one scent, but many mixed together. It's the same reason you wouldn't talk about a plate of food with the word scent. The plate probably has the smell of meat and a couple of different herbs and vegetables all mixed together. Aroma just means a pleasant smell, and fragrance means a pleasant or sweet smell. In this context they are both equally good to use.