Common lambsquarters

About

Lambsquarters is one of the most common garden weeds in the country, a fast, upright annual that can top 5 feet. It is a heavy feeder that steals nutrients and water from crops, and one plant can leave tens of thousands of long-lived seeds behind.

Also called lamb's quarters, lambsquarters, fat hen, goosefoot, white goosefoot

How to identify it

Look for

Young leaves and shoot tips look dusted with white, grainy meal (tiny wax beads), and the leaves are dull gray-green, roughly diamond or goose-foot shaped with wavy teeth. Stems are ridged, hairless and often streaked with purple or red. Tiny green, petal-less flowers sit in dense, mealy clusters at the stem tips.

Look-alikes

Other goosefoots, such as nettleleaf goosefoot, look very similar, and young pigweeds sprout at the same time; the white mealy coating on new growth is the best clue for lambsquarters.

Where it grows

Vegetable gardens, flower beds, new plantings, field edges and other bare, disturbed soil in sun.

When

Sprouts mostly in spring but keeps coming all season; it flowers from early summer into fall, and seeds can be ripe just 2 to 3 weeks after flowering starts.

How it spreads

Seed only: a typical plant makes about 30,000 seeds and big ones far more, and the seeds can stay alive in the soil for decades.

Most common in

What to do, gentlest first

Start at the top. Weed killers are a last step; always read and follow the label.

1. Never let it go to seed Prevent

   Pull or cut plants before they flower. Seeds can ripen 2 to 3 weeks after flowering begins, and each plant you stop saves you years of seedlings.

2. Hoe or pull young seedlings By hand

   Hoe or pull when plants are small; it has a taproot, so pull steadily from the base. Seeds sprout from the top inch of soil, so shallow hoeing works well.

   Don't compost plants that have flowered.

3. Mulch bare soil Barrier

   Cover beds with mulch: at least 2 inches of loose straw, or about 3 inches of bark or wood chips in shrub and flower beds.

4. Corn gluten meal pre-emergent Organic spray

   Iowa State lists lambsquarters among the weeds corn gluten meal can stop as they sprout. Spread it before the weed seeds germinate (about 20 pounds per 1,000 square feet) and water it in lightly; it does nothing to plants that are already up.

   It also stops seeds you sow, so don't use it where you plan to plant seeds soon. Heavy rain right after spreading weakens it.

5. Burn down seedlings with a contact spray Organic spray

   Horticultural vinegar (acetic acid), fatty-acid soap, pelargonic acid or clove-oil sprays burn what they touch within hours. They work best on young seedlings in warm, sunny weather, and you will need to repeat, because they don't move into roots and bigger plants regrow.

   They kill any plant they touch, so shield crops. Strong vinegar can burn skin and eyes; wear goggles and gloves and follow the label.

6. Spot spray or use a garden-labeled pre-emergent Conventional spray

   In landscape beds, WSU lists glyphosate as a spot spray and trifluralin as a pre-emergent; in lawns, 2,4-D, MCPP, dicamba or triclopyr control it.

   Read and follow the label. Many lawn weed killers also kill or damage vegetables and flowers, so keep spray and drift off garden plants.

Uses, wildlife and pets

Edible?

Clemson and NC State Extension note that young leaves and shoots are edible, best cooked, because the plant holds saponins and oxalates that can upset the stomach if you eat a lot, especially raw. Only pick young plants you are sure of, from ground that hasn't been sprayed or treated, since several goosefoots look alike.

Not 100% sure? Don't eat it. Never pick from ground that may have been sprayed, or along roads and railways.

For wildlife

The leaves feed many caterpillars, and songbirds and small mammals eat the seeds (NC State).

Pets

Not listed by the ASPCA. NC State rates it low in toxicity; large amounts can harm livestock.