Viola, English Violet, Garden Violet, Sweet Violet 'White Czar'

'White Czar' is a white-flowered cultivar of our native marsh blue violet, V. cucullata. It is aggressively weedy, self-sowing with aband...Read Moreon. It has no fragrance.

Not to be confused with V. odorata 'Czar', which has fragrant purple flowers that smell like raspberries, and isn't hardy north of Z6.

Bluestone sells V. cucullata 'White Czar' under the wrong species name.

In May when this plant is entirely covered with pure white flowers, it can be quite breathtaking. The leaves stay attractive all summer. ...Read MoreIts drawback is it can be invasive and its roots are very tenacious making it rather difficult to pull out, even when small. Once established, I believe it impossible to eradicate.
I deal with it this way, after the spring show, I use a spading fork to remove many of them to give the newly planted annuals a chance to grow. Next Year, it will start all over again