What herbicide do I have to use to kill wild violets?
This article will have additional info to help: https://www.gardeningknowhow.com/ornamental/bulbs/violet/kill-wild-violets.htm
You will want to use something that gets to the root of the plant or it will continue to pop up on you. Something like RoundUp or there is a Spectricide product as well. Cannot remember the name.... Just be sure it says that it will kill the root too and not just the top part of the plant.
Should I cut back wild violets in the fall?
You don't have to. They will die back on their own for winter. However, it will not harm the plants should you choose to do so.
I have many violets in my rocky garden, in full sun, full shade and everything in between. They filll lots of spaces and look very health, but hardly ever bloom. Is there something I can do?
Hopefully, this article will help: https://www.gardeningknowhow.com/ornamental/bulbs/violet/wild-violets-care.htm
If the soil is poor, some compost and/or fertilizer should help them bloom.
I assume birds are the reason my flower garden first came to have while violets - as purple violets were planted and babied by me. Last year I removed ALL the white violet plants; however, this year all I have are white violets. Is it possible soil conditions caused my purple violets to lose their color? I love the color purple; will I need to replant? Thank you so much for your answer; I've tried researching it online but cannot find any definitive answer as to soil condition and color of the flower.
No, the color of wild violets does not change. If you have lots of white ones, then it is most likely due to birds, as you originally thought. And they are prolific spreaders, self-seeding as well. Generally, the purple violets begin blooming just following the white ones (at least that's been the case with mine). I have a bed filled with white right now but in another couple weeks or so, these will fade, giving way to the purple blooms that are also planted in the bed. I'm fairly confident that your purple violets will begin blooming soon, coloring the garden with purple.
What can I do to rid my lawn of wild violet? I think I've tried everything but digging them up.
This article will help: https://www.gardeningknowhow.com/ornamental/bulbs/violet/kill-wild-violets.htm
When we bought our house ten years ago, there was a small area by our front porch that had invasive purple wild violets. They never spread to any other place or neighbors' yards and I loved the heart-swirl shaped leaves and tiny purple flowers. Strangely a construction crew pulled them out, five years ago, to change the route of a waterline. They haven't grown back well at all and I have searched and asked at countless sites for where to purchase the seeds. Would you have a site or telephone number? Thank you for your time.
I would personally check on ebay. You may be able to find someone on there selling them. I have found a surprising number of hard to find plants and seeds on ebay.
They keep coming even though dug up the year before.
This article is addressing your problem: https://www.gardeningknowhow.com/ornamental/bulbs/violet/kill-wild-violets.htm