Taraxacum officinale
broadleaf weedUSDA zones 2–11Active: spring, fallThe most recognizable lawn weed in North America. Produces bright yellow flowers that mature into white seed heads. Deep taproot makes complete removal difficult.
Rosette of deeply toothed leaves; hollow stems exude milky sap; yellow composite flower heads; fluffy white seed puffs.
Pull entire taproot when soil is moist. Incomplete removal leads to regrowth.
When: Best in spring when soil is wet after rain
Mow at 3-4 inches and fertilize to crowd out dandelions. Dense turf prevents seed germination.
When: Ongoing throughout growing season
Spray horticultural vinegar (20% acetic acid) directly on crown. May require repeat applications.
When: Apply on hot, sunny day for best results
Selective broadleaf killer. Apply when dandelions are actively growing.
When: Apply in fall for best results when plants store energy in roots
Active ingredient: 2,4-D — e.g. Ortho Weed B Gon, Trimec
More effective than 2,4-D on mature dandelions. Systemic kill to the root.
When: Apply in fall when plants are pulling nutrients to roots
Active ingredient: Triclopyr — e.g. Ortho Weed B Gon Chickweed Killer
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.
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