List of beneficial weeds

This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by expanding it with reliably sourced entries.

This is a list of undomesticated or feral plants, generally considered weeds, yet having some positive effects or uses, often being ideal as companion plants in gardens.

Beneficial weeds can accomplish a number of roles in the garden or yard, including fertilizing the soil, increasing moisture, acting as shelter or living mulch, repelling pests, attracting beneficial insects, or serving as food or other resources for human beings.

Chart

Beneficial Weed Chart
Common name	Scientific name	Companion plant for	Attracts/hosts	Repels	Traps	Edibility	Medicinal	Avoid	Comments
Bashful Mimosa	Mimosa pudica	ground cover for tomatoes, peppers	predatory beetles				Its extract immobilizes the filariform larvae of Strongyloides stercoralis in less than one hour.^[1] In contemporary medicine, Mimosa pudica is being investigated for its potential to yield novel chemotherapeutic compounds. It contains an alkaloid called mimosine, which has been found to have potent antiproliferative and apoptotic effects.^[2]		Used as a natural ground cover in agriculture
Caper Spurge	Euphorbia lathyris			Moles			Used in folk medicine as an antiseptic and purgative		Many domesticated animals can eat it, although it is poisonous to humans.
Clover	Trifolium	Brassica (cabbage and cousins like broccoli and cauliflower), corn, cucurbits (cucumber, squash, melons, gourds) -- Along with fertilizing the soil, this plant provides a humid microclimate that benefits many plants by stabilizing their moisture			Rabbits	This legume is a high-protein source of food, but generally only eaten in survival situations		Nightshades (tomato, pepper, eggplants)	This legume hosts nitrogen-fixing bacteria in its roots, and therefore fertilizes the soil for neighboring plants. It is also used as a fallow plant by some farmers, and is a very popular fodder plant.
Cocklebur	Xanthium	Grasses and grains		Army worms			Is used in Chinese medicine	Poisonous to some lifestock	Also used for yellow dye
Common name	Scientific name	Companion plant for	Attracts/hosts	Repels	Traps	Edibility	Medicinal	Avoid	Comments
Crow garlic	Allium vineale	fruit trees, nightshades (tomatoes, peppers, potatoes, etc.), brassicas (cabbage, broccoli, kohlrabi, etc.) carrots		slugs, aphids, carrot fly, cabbage worms^[3]		Can be used like conventional chives	3-mercapto-2-methylpentan-1-ol in onion was found to have an antioxidant potent that inhibits peroxynitrite induced diseases.^[4]	beans, peas, parsley	This is a wild cousin of onions and garlic
Dandelion	Taraxacum	Various grains, tomato plants	Honeybees	Armyworms		In season, leaves and flowers are edible	Used as a diuretic in herbal medicine		Tap root breaks up hardened soil and brings up nutrients from deep down, benefiting plants with weaker or shallower roots without competing with them.
Goldenrod	Solidago	Pear trees, Black Locust Tree, Sugar Maple	Predatory wasps	Various Lepidoptera larvae			Numerous medicinal uses		Contains latex, the automobile given to Thomas Edison by Henry Ford had tires made from goldenrod latex
Ground Ivy	Glechoma hederacea	Tomatoes, peppers, cucumbers and relatives (squash, melons), broccoli, brussels sprouts, cauliflower		cabbage worms, cucumber worms and beetles, tomato horn worms, others		Can be used in herbal teas	Used in the traditional medicine of Europe going back thousands of years. Inflammation of the eyes, tinnitus, a diuretic, astringent, tonic and gentle stimulant. See here for more.		This wild mint makes a good ground cover companion plant, creating a humid microclimate, covering up nearby plant scents, and distracting pests from companion crops.
Common name	Scientific name	Companion plant for	Attracts/hosts	Repels	Traps	Edibility	Medicinal	Avoid	Comments
Horsenettle	Solanum carolinense		Predatory beetles			The berries of this fruit may be edible when cooked	Ripe fruit, when cooked, is used by herbalists as a diuretic and sedative
Milkweed	Asclepias	Corn, basil, potatoes	Predatory wasps and the Monarch butterfly	Wireworms			Folk remedy for warts, sap reduces poison ivy symptoms		Can be used as a more effective insulator than goose down. Emits a chemical that breaks up hard soil, allowing nearby plants to develop healthier root systems. Basil repels some insects that attack milkweed.
Nasturtium	Tropaeolum	Most vegetables, especially brassica (cabbage, broccoli, et al.), cucurbits (cucumbers, melons, squash) and solanum (tomatoes, potatoes, peppers, etc.)	Predatory wasps	Squash bugs, cucumber beetles, striped pumpkin beetles, woolly aphids	trap crop for caterpillars and black aphids	All parts of this plant are edible, flowers and leaves make brilliant salad decoration			Considered one of the "magic bullet" companion plants, benefiting almost any crops around it in some way, and not known to hurt any
Nettle	Urtica dioica	broccoli, tomato , Valerian, mint, fennel				Despite its "sting", young plant parts are edible, as is much of the plant when blanched or otherwise prepared. Also makes a nutritious herbal tea	One of the most-used plants in herbal medicine, with a long list of benefits		Also once grown as a crop for its fiber. Its juice was once used in the place of rennet in cheese-making. It was also a source of "green" for dye. It can still be used as a high-protein additive in animal feed, once dried.
Common name	Scientific name	Companion plant for	Attracts/hosts	Repels	Traps	Edibility	Medicinal	Avoid	Comments
Purslane	Portulaca oleracea	corn, solanums like tomatoes and peppers				Purslane is eaten throughout much of Europe and Mexico. It contains more Omega-3 fatty acids than any other leafy vegetable plant. It can be eaten in salad, stir-fried, or cooked like spinach. berries can be eaten like capers	In Traditional Chinese Medicine, it is used to treat infections or bleeding of the genito-urinary tract as well as dysentery. It may also be applied topically to relieve sores and insect or snake bites on the skin.	Dill, parsnip, radish	Breaks up hard soil and hardpan, brings nutrients and water up from deeper than crops can reach, provides healthy ground cover, stabilizing soil moisture
Queen Anne's Lace	Daucus carota	Nightshades (especially tomatoes), alliums (onions, chives), lettuce	predatory wasps and flies			Young roots are edible	Some recent scientific support for its historic use as a herbal contraceptive	Dill, parsnip, radish	Do not confuse with its poisonous cousin, water hemlock
Wild Mustard	Brassicaceae	Grape vine , radish, non-mustard brassica, including cabbage, cauliflower, broccoli	Ladybugs		Traps various brassica pests, including aphids	Seeds and leaves are edible		beets	Domesticated mustard is a hybrid of three different species of wild mustard, all of which are still used in some places for food. This is known as the Triangle of U.
Wild Rose	Rosa	Strawberries, grapes, roses		Rodents and deer	Traps Japanese beetles	Rose hips can be used in herbal teas	Same medicinal benefits as domesticated rose		This includes the feral multiflora rose, brought to the US both for use as root stock for domesticated roses, and as a "natural fence" for lifestock. In the mid 20th century miles of multiflora rose hedge were planted in sequence.
Common name	Scientific name	Companion plant for	Attracts/hosts	Repels	Traps	Edibility	Medicinal	Avoid	Comments
Wild Vetch	Vicia americana	Pepper and tomato plants, brassica (cabbage, mustard, broccoli), other plants needing high nitrogen	Provides ground cover for predatory beetles						This legume fixes nitrogen, allow it to grow in a tomato garden only until time to plant, as ground cover. But can be left growing among brassica for additional nitrogen and microclimate

Categories of beneficial weeds

Pest-repellent

Neem—repels leaf eating insects

Edible

Borage—all parts have various medicinal purposes, with the edible flowers being used in desserts.
Burdock—roots are edible (as are the stalks, but particularly the young leaves ^[5])
Chickweed (Stellaria media) -- used in salads and also as ground cover
Cornflower various colours; can be served as edible garnish to decorate salads.
Horsetail—primeval plant that produces its own vitamin D & is high in silica; tops are very similar to & may be eaten like asparagus
Lamb's quarters—leaves and shoots, raw, also prevents erosion, also distracts leaf miners from nearby crops
Nettle—young leaves collected before flowering used as a tea or spinach substitute. Plants have use as compost material or for fibre.
Purslane—prepared raw for salads or sautéed
Shepherd's purse—leaves are edible and often sautéed or blanched
Watercress—can be eaten raw or cooked; is considered a weed in some cultures (caution required when harvesting wild due to the risk of contracting potentially fatal liver fluke)

Habitat for beneficial insects

Wild blackberry—attracts predatory insects, and produces berries
Motherwort—attracts bees
Joe-Pye weed—habitat for pollinators and predatory insects
Aster—habitat predatory insects

Shelter plants

Normal grass can be used as ground cover, especially in nitrogenous soils.

Trap crops

Trap crops draw potential pests away from the actual crop intended for cultivation.

Cowpea—attracts ladybird beetle, so planting around cotton fields protects them from sucking insects. It serves as source of food and niche.

Medicinal use

Rumex—Dock. Commonly grows in association with nettle, is rumoured to cure or ease their sting. Crush a leaf before applying to affected area. Liver tonic, increases iron levels in the blood, regulates hormone levels and reduces menstrual flow and cramping.
Urtica dioica—Stinging nettle. Nutritive tonic, diuretic. Restorative to the adrenals and kidneys. Highly nutritive. Can be eaten after cooking to remove the stinging properties. Stinging nettle has been used as a successful pain reliever for arthritis by stinging the affected area with the raw plant.^[6]
Arctium lappa—Burdock. The root is used to stimulate detoxification of the lymph and liver, known as a "blood purifier." It also has diuretic and diaphoretic properties.
Taraxacum officinale—Dandelion. The leaves are a tonic to the kidneys, being one of the few diuretics that does not deplete the body of potassium. The whole plant, especially the root, is a detoxifying tonic for the liver. The whole plant is bitter and can be used as a digestive stimulant.^[7]
Capsella bursa-pastoris—Shepherd's Purse. Used to stop bleeding.^[8]
Galium aparine – used in folk medicine to make poultices.^[9]
Stellaria media -- Chickweed. One of the most nutrient dense plants, full of antioxidants. Effective for skin conditions when infused into oil. Dissolves cysts and lumps.^[10]
Plantago spp—Plantain, Ribwort, Pig's ear. Wound healing herb. "Not only does plantain increase the speed of healing, it also relieves pain, stops bleeding, draws out foreign matter, stops itching, prevents and stops allergic reactions from bee stings, kills bacteria, and reduces swelling." Mucilaginous. The seed husks are the main ingredient in psyllium laxatives. Identify this common weed by the 5 parallel veins on the underside of the leaf.^[11]^[12]
Hypericum perforatum—St John's Wort. Tincture is used as an anti-viral and for muscle aches, shingles, sciatica, back pain, neuralgia, and headaches including migraines. Infused oil can be used to treat sore muscles, cold sores and genital herpes, and can be used as a sunscreen.^[13]
Achillea millefolium—Yarrow. Antibacterial, pain relieving. Herb for wounds. Regulates blood flow, so that it stops excessive bleeding while also preventing blood from pooling. Can be used to prevent and treat colds and flu. Diaphoretic. Digestive stimulant.^[14]^[15]
Malva spp—Mallow. Whole plant is mucilaginous, extracted in cold water or vinegar, which is soothing internally (easing sore throats, upset tummies, heart burn, irritable bowel, colic, and constipation) and externally (relieving bug bites, burns, sprains, and sore eyes).^[16]
Impatiens capensis—Jewelweed. Often grows near poison ivy and can be used as an antidote (for poison oak as well) ^[17]
Verbascum spp—Mullein. The leaves are an expectorant, stimulating coughing to clear the lungs. An infused oil can be used for ear infections. All parts are stimulating to the lymphatic system and are helpful for any ailment related to the alignment of joint, bone or tissue.^[18]
Bellis perennis—Daisy. Relieves headaches, muscle pain and allergy symptoms. Different from the native daisy (Lagenifera petiolata).^[19]
Ambrosia trifida—Giant ragweed. A tincture can be made and used in small doses to treat ragweed (and other) allergies.^[20]

Other

Nightshade—breaks up hardpan, allowing roots to grow deeper

References

↑ Robinson RD, Williams LA, Lindo JF, Terry SI, Mansingh A (1990). "Inactivation of strongyloides stercoralis filariform larvae in vitro by six Jamaican plant extracts and three commercial anthelmintics". West Indian Medical Journal. 39 (4): 213–7. PMID 2082565.
↑ "Antiproliferative effect of mimosine in ovarian cancer". Journal of Clinical Oncology. Retrieved 2010-01-13.
↑ nss abstracts
↑ Rose, Peter; Widder, S; Looft, J; Pickenhagen, W; Ong, CN; Whiteman, M; et al. (2003). "Inhibition of peroxynitrite-mediated cellular toxicity, tyrosine nitration, and α1-antiproteinase inactivation by 3-mercapto-2-methylpentan-1-ol, a novel compound isolated from Allium cepa". Biochemical and Biophysical Research Communications. 302 (2): 397–402. doi:10.1016/S0006-291X(03)00193-1. PMID 12604361.
↑
↑ http://www.animacenter.org/urtica.html
↑ http://botanical.com/botanical/mgmh/d/dandel08.html#med
↑ http://botanical.com/site/column_susun/susun_weedwalk.html
↑ Schneider, Anny & Mellichamp, Larry (2002). Wild Medicinal Plants: What to Look For, When to Harvest, How to Use. Stackpole Books. p. 73. ISBN 9780811729871.
↑ http://botanical.com/site/column_susun/susun_weedwalk.html
↑ http://botanical.com/site/column_susun/susun_weedwalk.html
↑ http://www.thetruthsource.org/helping/20-edible-medicinal-weeds-in-your-backyard
↑ http://botanical.com/site/column_susun/susun_weedwalk.html
↑ http://botanical.com/site/column_susun/susun_weedwalk.html
↑ http://www.thepracticalherbalist.com/component/content/article/40-herbal-encyclopedia/102-yarrow-the-wound-healer.html
↑ http://botanical.com/site/column_susun/susun_weedwalk.html
↑ http://www.thetruthsource.org/helping/20-edible-medicinal-weeds-in-your-backyard
↑ http://bearmedicineherbals.com/a-golden-torch-mullein%E2%80%99s-healing-light.html
↑ http://botanical.com/site/column_susun/susun_weedwalk.html
↑ http://www.herbalencounter.com/2011/07/01/ragweed-tinture-tea-or-powder-from-dried-leaves-of-young-plant-may-help-to-overcome-ragweed-allergies-naturally/

Peterson, L.A. & Peterson, R.T. (1999). A Field Guide to Edible Wild Plants: Eastern and central North America. Houghton-Mifflin.
Duke, J.A., Foster, S., & Peterson, R.T. (1999). A Field Guide to Medicinal Plants and Herbs of Eastern and Central North America. Houghton-Mifflin.
Gibbon, E. (1988). Stalking the Wild Asparagus. Alan C. Hood & Company.
Sharma, O.P., R.C. Lavekar, K.S. Murthy and S.N. Puri. (2000). Habitat diversity and predatory insects in cotton IPM : A case study of Maharashtra cotton eco-system. Radcliffe’s IPM world textbook. http:// www.ipmworld.umn.edu/chapters/ sharma.htm. Minnesota University, USA