Viola sororia
broadleaf weedUSDA zones 3–9Active: spring, fallPerennial wildflower that aggressively colonizes shady, moist lawns. Heart-shaped leaves and purple flowers are attractive but it crowds out turf.
Heart-shaped leaves with scalloped edges; blue-violet flowers in spring; thick, waxy leaves; rhizomatous clumps.
Violets indicate shade and moisture. Reduce shade if possible; some choose to embrace them.
When: Assess conditions in spring
Dig out clumps including rhizomes. Labor-intensive for large infestations.
When: Dig in spring when soil is moist
Horticultural vinegar can burn leaves but waxy coating limits absorption. Repeat applications needed.
When: Apply repeatedly during active growth
Most effective option for violets. The waxy leaves resist many herbicides. Use with surfactant.
When: Apply in fall with surfactant for best leaf penetration; repeat in spring if needed
Active ingredient: Triclopyr — e.g. T-Zone, Turflon Ester
Grass safety: always match herbicides to your grass species — products safe on Kentucky bluegrass can kill St. Augustine or centipede. Lawn Guardian checks this automatically against your lawn profile.
Lawn Guardian turns this guidance into a schedule timed to your USDA zone and this week's actual weather — and adapts every time you log what you've done.
Get your free plan