Hi! Welcome to the forum. There is currently only 1 thing to craft with Fellora blossom which is the Transformation tonic (Potion Shop, 2 hours - 5 fellora blossoms, 3 glimmerdust, 3 water).
This craft is accessible if you're level 31+ and you have completed "Lesson Three" from Castle Story: 06/05 Update Three Lessons For Ivy. If not, then yes they are a great source of income. I plant these as well as you can make over 100,000 net profit in coins once you replant. Plus they are super pretty!