Lambsquarters
Broadleaf weed
Lambsquarters (Chenopodium album) is one of the most common summer annual broadleaf weeds in North American gardens, lawns, and crop fields. Gardeners and growers notice it because it germinates early, grows fast, and can quickly overtop young vegetables and slow-starting crops.
How to identify it
Young plants form a low rosette of leaves that are roughly diamond or goosefoot shaped, with coarse, irregular teeth along the edges. The leaves and stems often carry a fine, whitish, mealy coating that rubs off, and the undersides of the leaves usually look gray-green and dusty. Stems are upright, ridged, and frequently streaked with pink or light red, and mature plants can reach 1 to 6 feet tall. Flowers are small, green, and clustered in dense spikes at the stem tips and upper leaf joints, and the plant grows from a shallow, branched taproot.
Where it grows
Lambsquarters thrives in disturbed, fertile ground, so it is common in vegetable gardens, flower beds, cropland, field edges, and freshly tilled or bare soil. It is mainly a warm-season weed that emerges from spring through summer and completes its life cycle in a single growing season. It spreads only by seed, and a single mature plant can produce tens of thousands of seeds that stay viable in the soil for many years.
Why it is a problem
Because it grows quickly and tall, lambsquarters competes aggressively with crops and vegetables for light, water, and soil nutrients, and it is especially good at pulling up nitrogen. Its huge, long-lived seed bank means one season of uncontrolled plants can create a weed problem that returns for years. The plant also releases large amounts of pollen that can contribute to seasonal allergies for some people.
How to manage it
The most effective approach is to prevent seed production, so pull or hoe young plants while they are small and well before they flower, taking care to remove the shallow taproot. A thick layer of organic mulch in garden beds blocks light and greatly reduces new seedlings, and keeping soil covered with crops or cover crops limits the bare, disturbed ground this weed favors. In lawns and turf, dense, healthy grass shades out seedlings, so proper mowing, watering, and soil care are strong long-term defenses. Bag and remove any plants that have already set seed rather than leaving them on the soil or adding them to a cool compost pile.
Commonly confused with
Lambsquarters is often confused with pigweed (Amaranthus species), which has similar upright growth but lacks the whitish mealy coating and usually has more rounded or oval leaves. Young plants can also resemble edible relatives like garden spinach and orach, so gardeners should identify carefully before removing or handling seedlings.
General guidance for US lawns and gardens, focused on prevention and non-chemical control. For a confirmed identification and options specific to your area, contact your local Cooperative Extension office. Page updated Aug 4, 2026.