Lamb’s Quarters is also known as:
- Wild Spinach
Flowers: Tiny, greenish flowers form dense clusters or spikes in the leaf axils and at the stem tips.
Stem: Mature plants range from 0.2 – 2.0 m in height. The stems are branched or unbranched, smooth, green, and may have reddish longitudinal stripes and ridges.
Leaves: Egg- or diamond-shaped, greyish-green, and dusty white on the undersides. The upper leaves are smaller and narrower and the small white hairs give the leaves a mealy appearance. Leaves are between 3 – 10 cm long and are odourless when crushed.
Fruit: Small seeds, 1 – 1.5 mm in diameter, are enclosed in a thin, smooth whitish pericarp. The pericarp is lost when seeds dry.
Redroot Pigweed (Amaranthus retroflexus) seedlings have a prominent midvein on the first leaf while Lamb’s Quarter do not.
Common Orache (Atriplex patula) has an opposite arrangement of the first several pairs of leaves and branches.
The leaf base has a lobe on each side.
Habitat and Origin
Native to Europe, Lamb’s Quarters was a commonly eaten green in spring and summer. It is an excellent source of vitamin A and iron when eaten in moderation.
Lamb’s Quarters is a versatile plant, common to low and middle elevations. It grows well in disturbed sites, particularly in cultivated land. Lamb’s Quarters can be found in gardens, croplands, old fields, weedy meadows, roadsides, and railways.
Propagation & Vectors of Spread
Lamb’s Quarters is an annual that spreads through seeds. Each plant produces about 72,000 seeds. The majority of seeds germinate at the beginning of the growing season, though some will also germinate later in the summer. Seeds can remain dormant in the soil for 20 years or more.
Lamb’s Quarters spreads due to its high rate of seed production. It is also a common contaminant in grass seed. It can be spread through human activity, gardens, and farm cultivation.
Ecological & Economic Impacts
- Causes sickness and death in humans and animals if ingested in large quantities.
- Can cause photosensitization after ingested.
- Harbours pests.
- Reduces crop yields.
What Can I Do?
Lamb’s Quarters is currently found throughout the Sea to Sky Corridor, so the best approach to controlling its spread is by PREVENTION.
Learn to identify Lamb’s Quarters: use the images presented in this profile page to learn how to identify Lamb’s Quarters.
What to do if you spot it: You can report any Lamb’s Quarters sighting by clicking here.
- Regularly monitor properties for weed infestations.
- Ensure soil and gravel are uncontaminated before transport.
- Check wildflower mixes to ensure that they do not contain Lamb’s Quarters.
- Ensure that plants are disposed of in a garbage bag if found in floral arrangements to prevent seeds from spreading.
- Do not unload, park or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles, or clothing used in such areas and wash equipment and vehicles at designated cleaning sites before leaving infested areas.
- Do not plant Lamb’s Quarters in a garden, no matter how well-contained its enclosure may seem.
- Do not move soil that has been contaminated with Lamb’s Quarters.
- Do not compost.
- Regular mowing/tilling before the plant goes to seed will reduce weed progression; plant material can be left at the site to decompose.
- In the post-flowering stage, all plant parts must be bagged and deeply buried at the landfill.
- Lamb’s Quarters has a short taproot and can be hand-pulled easily.
- Lamb’s Quarters can be controlled through herbicide in most crops.
- Pre-emergent herbicides are recommended. Fluroxypyr with MCPA and fluroxypyr with 2,4-D are identified as effective herbicides for this plant.
- It is worth noting that some Lamb’s Quarters populations are resistant to Group 5 and Group 2 herbicides.
- Any herbicide applications must be applied through a certified pesticide applicator. We recommend that any herbicide application is carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.
Field mice, sowbugs, millipedes, crickets, slugs, and carabid beetles feed on seeds lying on the soil surface, though they don’t offer significant control.
- Eat The Invaders, Lamb’s Quarters, http://eattheinvaders.org/lambs-quarters/
- E-flora BC, Lamb’s-quarters, http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Chenopodium%20album
- Manitoba Agriculture and Resource Development, Lamb’s Quarters, https://www.gov.mb.ca/agriculture/crops/weeds/lambs-quarters.html
- Michigan State University, Common Lambsquarters, https://www.canr.msu.edu/weeds/extension/common-lambsquarters
- Michigan State University, 2017 Weed Control Guide for Field Crops, https://www.canr.msu.edu/uploads/resources/pdfs/2017_weed_control_guide_for_field_crops_(e0434).pdf
- Minnesota Wildflowers, Lamb’s-quarters, https://www.minnesotawildflowers.info/flower/lambs-quarters
- Ontario Ministry of Agriculture, Food, and Rural Affairs, Ontario Weeds: Lamb’s quarters, http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/lambs_quarters.htm
- WeedInfo, Lamb’s-quarters, http://www.weedinfo.ca/en/weed-index/view/id/CHEAL