6 Most Common Weeds and How to Deal with Them

While one gardener’s weed is another’s pretty green thing, most everyone will agree that uninvited plants simply get in the way of what we want to grow. Here are profiles of six of the most common annoying weeds to help you identify and get rid of them.

Dandelion

Taraxacum Officinale

• Perennial
• Spreads by seeds
• Height to 1 foot
• Found in the U.S. (not southernmost TX, CA, AZ, and FL) and southern Canada
• can flower at any time when temperatures permit.

Dig out the entire taproot, hoe plants before they flower, and spread corn gluten in early spring to suppress seedlings.

Annual Sow-Thistle

Sonchus Oleraceus

• Perennial
• spreads by seeds
• height to 18 inches
• found across the U.S. and southern Canada, mostly in lawns
• flowers July through October

Dig out entire root, or cut at soil line until root stops sprouting. Aerate and add organic matter to lawn. This weed tolerates compacted soil and shade.

Carpetweed

Mollugo Verticillata

• Annual
• spreads by seeds
• stems grow to 1 foot
• found across the U.S., except for ND and parts of MT and MN
• flowers June through November

Hoe or pull plants when they appear. Mulch deeply to smother any seedlings.

Large Crabgrass

Digitaria Sanguinalis

• Annual
• spreads by seeds/roots at leaf joints
• height to 3 feet
• found across the U.S., except ND and parts of SD, MT, and MN
• flowers June through October

Pull out entire plant, including roots. Mulch or let grass grow to 3 to 4 inches high to prevent seed germination. Mowing will not kill this plant. Spread corn gluten in early spring to suppress seedlings.

Poison Ivy

Rhus Radicans

• Perennial
• spreads by creeping rootstock
• found across U.S. (not AK or CA) and southern Canada, as vine or shrub
• flowers in May and June

Entire plant is toxic. Wear protective gloves and clothing. Cut plant at base, let it dry out, and bury or put vines in trash. Do not compost or burn (inhaling smoke can be fatal). Mulch with cardboard.

Prickly Lettuce

Lactuca Serriola

• Annual/biennial
• spreads by seeds
• height to 5 feet
• found across the U.S. except for southernmost FL
• flowers July through September

Hoe or pull plants as you see them, or cut taproot below soil line. Wear gloves. Attracts beneficial insects and so may be fine for outlying areas, but can play host to lettuce diseases.