Take back your yard from weeds
lawn back where it should be. ~ Elizabeth
A) Before I answer your question Elizabeth, I have a few of my own ... and these should apply to everyone who wants the perfect lawn.
First, why are the violets so bad in your lawn? Many of the weeds that people are so desperate to eradicate in their lawns are actually beneficial to local insect populations — and even to the soil and water tables below the grass. The violets are probably one of the hardest weeds to get rid of due to their waxy leaves and their ability to spread via seeds or underground roots. There are very few chemicals that will kill this weed and there are zero that are available in your area. There is lots of evidence that wild violets prefer acidic soil so adding garden lime can help ... sometimes. There are also reports that wild violets prefer soil that is low in calcium. Neither of these solutions are really going to be cost effective or give you substantial results.
My second question is not going to make me any friends here, but why don’t you get out and dig them up? This is the only way that you are going to save your existing lawn and get rid of the violets. Manual digging sounds a lot like exercise, and many people find excuses as to why they can’t get outside and do the work. My 90-yearold grandma still gets out and weeds for 10 minutes everyday. She just keeps at it. No sprays, no chemicals, just exercise.
For the violets, I recommend using a longer-handled poaching spade, originally designed for digging rabbits out of holes. This will allow you to get all of the clumps and roots out. Start now and dig out two clumps a day until the ground freezes. Just two clumps a day is not a major commitment but I promise, it will put a large dent in the violet population. If you just keep at it, you will have gotten rid of the invasive weed and aerated the lawn at the same time.
Finally, can you live without the perfect green lawn? More and more homeowners are moving away from grass and adding all kinds of flowering bulbs into the lawn. Things like crocus and mini daffodils are happy growing up in the lawn and by the time the lawn is ready for a trim, they have collected enough sunlight to create bulbs for next year. Violets are not grass ... I know, but they have very few insect predators, are healthy with very little fertilizers and really require no work.
Probably not the solution you were looking for but I hope it answers some of your questions and helps you realize that leaving them alone might be your best answer after all.
Violets are probably one of the hardest weeds to get rid of due to their waxy leaves and their ability to spread via seeds or underground roots.