Violet is a color closer to purple than blue. And what a person sees may be more in the eye of the beholder, how bright the light is, and how old the bloom is. There are also violets that are mostly white and some are even yellow.
Violets are in the plant genus Viola which includes the violets (small flowers) and pansies (large flowers). There are some 30 species of violets in Ohio, some being very common (e.g. common blue violet (V. sororia)) and some being fairly rare (e.g. southern wood violet (V. hirsutula)) restricted to specific habitats. The wild violets are hardy perennials that are spread by seed and underground, horizontal stems called rhizomes.
Are violets desirable wildflowers or weeds? The answer to that question depends on the person who has the violets. Violets are beautiful little flowers that bloom from early spring into the summer and sometimes even into the fall. Four common species that can be found in most parts of Ohio are the previously mention common blue violet (V. sororia), a color variation of this violet, the confederate violet (V. sororia f. priceana), the striped white violet (V. striata), and the downy yellow violet (V. pubescens).
Given the opportunity, violets can spread to cover large areas. Unfortunately, they sometimes spread into areas where people would prefer that they not spread such as into lawns and flower gardens. They can be aggressive and choke out other desirable plants.
Hand-pulling violets is not easy, they tend to break easily near the rhizome. Thus, unless one digs below the rhizome to remove it, the violets will “resprout”.
Violets in turfgrass can be reduced by increasing the frequency of mowing (i.e. more than once a week) to continuously cut off their leaf tissue. This does not mean one should cut the lawn to a shorter height, maintain a 2 ½-3” minimum height. Cutting shorter than this height will open opportunities for other weeds to move into the lawn and reduce the vigor of the turfgrass.
Even management with herbicides can be difficult. The leaves of violets have a thick, waxy cuticle which is resistant to penetration. Herbicides with the active ingredient triclopyr are effective, but it may require multiple treatments over a couple of years to rid an area of unwanted violets. Triclopyr is active against numerous tough to control plants (trees, shrubs, vines, weeds), so be very careful where this product is applied, how it is applied and how much is applied. When using pesticides, be sure to read all labels and follow instructions.