Why do wild violets not flower?

Question

They are planted in various parts of the garden in good soil, not soggy with some leaf matter, both in sun/shade. The leaves are big and healthy but alas no flowers.

Answer 1

There may be to much Nitrogen in the soil. This will cause lush greens and no flowers.
You can add phosphorous by using Bone Meal.
Here are a few links for you.

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/bone-meal-fertilizer.htm
https://www.gardeningknowhow.com/ornamental/bulbs/violet/wild-violets-care.htm