Weeds are present in nearly every Tennessee lawn. It’s important to remove weeds that are invasive, or just a plain nuisance, before the get a foothold in the lawn.
Onion grass is a common weed that plagues lawns in Tennessee and most of the United States. This weed has underground bulbs. Onion corms are capable of regenerating after weed killer is used and require multiple applications of glyphosate (RoundUp.) To prevent wild onion grass from spreading it’s best to dig out the corms, making sure to get any stray bulblets. Onion grass also spreads by seed if flowers are allowed to mature.
Thistles are vigorous roadside weeds that let loose a ton of billowy airborne seeds that invade suburban lawns. Thistles have the nagging quality of growing anywhere — in the lawn, under fences, and in nooks that make them difficult to remove. Thistles produce strong taproots that will grow back, even after weed killer is used. For a small population of thistles in the lawn, try killing the leaves with boiling water and cutting the tap root with a shovel, trowel, or weed removal tool. Weed killers are most effective when applied to thistles before the flowering stage. Cut or mow thistle leaves before applying weed killer, so enough herbicide will be absorbed. Tordon 22K and Vanquish are recommended for killing weeds on large amounts of land.
Spiny amaranth is one of the worst weed offenders. As the name implies, this form of pigweed has sharp spines, even small seedlings may have prickly spines. This is an incredibly invasive weed in Tennessee’s agricultural fields and has become resistant to many of the common herbicides. Glyphosate (RoundUp) is effective on pigweed but tilling and hoeing is still considered the best practice. Clip flowers to prevent seed dispersal. Always wear gloves when dealing with this weed as the spines can cause lingering pain.
Dandelions are one of the most prolific lawn weeds in Tennessee, spreading airborne seeds throughout the growing season. Dandelions are best controlled by digging-out the long fleshy tap root, which is capable of re-growing after weed killer has removed all of the leaves. Mechanical weed removal tools are available, which are safe and effective. For best results apply weed killer, like RoundUp, during the fall when the dandelion won’t be able to regenerate and make food to survive the winter.
Always read and follow weed killer directions carefully before using.
Kathryn Hatter, “How to Kill Onion Grass” GardenGuides.com
Emma Gin, “How to Control Musk Thistle” GardenGuides.com.
Weed Department Shawnee County, Kansas, “Musk Thistle and Specific Controls” Shawnee County, KS.
Kat Yares, “Pigweed Weed” GardenGuides.com.
PAN Germany, OISAT “Pigweeds” PAN Germany, OISAT Online Information Service for Non-Chemical Pest Management in the Tropics.
Dawn West, “Weed Control Tips to Defeat Dandelions” All About Lawns.