This is a list of undomesticated or feral plants, generally considered

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

s, yet having some positive effects or uses, often being ideal as

companion plant Companion planting in gardening and agriculture is the planting of different crops in proximity for any of a number of different reasons, including pest control, pollination, providing habitat for beneficial insects, maximizing use of space, and ...

s in gardens.

Beneficial weed Beneficial may refer to: Organizations * Beneficial Corporation, a consumer finance company founded in 1914 that was ultimately bought by HSBC Corporation ** Beneficial Loan Society, the former name of Beneficial Corporation ** Beneficial Finance, ...

s 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 Beneficial insects (sometimes called beneficial bugs) are any of a number of species of insects that perform valued services like pollination and pest control. The concept of ''beneficial'' is subjective and only arises in light of desired outcome ...

, or serving as food or other resources for human beings.

Chart

Categories of beneficial weeds

Pest-repellent

Neem ''Azadirachta indica'', commonly known as neem, nimtree or Indian lilac, is a tree in the mahogany family Meliaceae. It is one of two species in the genus '' Azadirachta'', and is native to the Indian subcontinent and most of the countries in Afr ...

—repels leaf eating insects

Edible

Blackberry The blackberry is an edible fruit produced by many species in the genus ''Rubus'' in the family Rosaceae, hybrids among these species within the subgenus ''Rubus'', and hybrids between the subgenera ''Rubus'' and ''Idaeobatus''. The taxonomy ...

—blackberries are rich in nutrients, and their thorny stems can form a barrier against some larger pest mammals. * Burdock—roots are edible (as are the stalks, but particularly the young leaves.) *

Chickweed ''Stellaria media'', chickweed, is an annual and perennial flowering plant in the family Caryophyllaceae.Fernald, M. L. 1950. “Gray's Manual of Botany”. Eight Edition. American Book Company, New York, NY. 1632 pp. It is native to Euras ...

(''Stellaria media'')—used in salads and also as ground cover. *

Cornflower ''Centaurea cyanus'', commonly known as cornflower or bachelor's button, is an annual flowering plant in the family Asteraceae native to Europe. In the past, it often grew as a weed in cornfields (in the broad sense of "corn", referring to gr ...

—various colors; can be served as edible garnish to decorate salads. * Flatweed—leaves are edible raw, while roots are edible after being roasted. *

Horsetail ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass ...

—primeval plant that is high in silica; tops are very similar to & may be eaten like asparagus. * Lamb's quarters—leaves and shoots, raw, also prevents

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is dis ...

, also distracts leaf miners from nearby crops. *

Nettle {{redirect, Nettle Nettle refers to plants with stinging hairs, particularly those of the genus '' Urtica''. It can also refer to plants which resemble ''Urtica'' species in appearance but do not have stinging hairs. Plants called "nettle" includ ...

—young leaves collected before flowering used as a tea or spinach substitute. Plants have use as compost material or for fibre. *

Purslane Purslane is a common name for several mostly unrelated plants with edible leaves and may refer to: * Portulacaceae, a family of succulent flowering plants, and especially: ** ''Portulaca oleracea'', a species of ''Portulaca'' eaten as a leaf vegeta ...

—prepared raw for salads or sautéed. *

Shepherd's purse ''Capsella bursa-pastoris'', known as shepherd's purse because of its triangular flat fruits, which are purse-like, is a small annual and ruderal flowering plant in the mustard family (Brassicaceae). It is native to eastern Europe and Asia minor, ...

—leaves are edible and often sautéed or blanched. *

Watercress Watercress or yellowcress (''Nasturtium officinale'') is a species of aquatic flowering plant in the cabbage family Brassicaceae. Watercress is a rapidly growing perennial plant native to Europe and Asia. It is one of the oldest known leaf v ...

—can be eaten raw or cooked; is considered a weed in some cultures (caution required when harvesting wild because of the risk of contracting potentially fatal liver fluke).

Habitat for beneficial insects

* Wild

blackberry The blackberry is an edible fruit produced by many species in the genus ''Rubus'' in the family Rosaceae, hybrids among these species within the subgenus ''Rubus'', and hybrids between the subgenera ''Rubus'' and ''Idaeobatus''. The taxonomy ...

—attracts predatory insects, and produces berries. * Motherwort—attracts bees. *

Joe-Pye weed ''Eutrochium'' is a North American genus of herbaceous flowering plants in the family Asteraceae. They are commonly referred to as Joe-Pye weeds. They are native to the United States and Canada, and have non-dissected foliage and pigmented flowe ...

—habitat for pollinators and predatory insects. * Aster—habitat for predatory insects.

Shelter plants

* Normal

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns a ...

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

Trap crops

Trap crop A trap crop is a plant that attracts agricultural pests, usually insects, away from nearby crops. This form of companion planting can save the main crop from decimation by pests without the use of pesticides. /sup> A trap crop is used for attracti ...

s draw potential pests away from the actual crop intended for cultivation. *

Cowpea The cowpea (''Vigna unguiculata'') is an annual herbaceous legume from the genus ''Vigna''. Its tolerance for sandy soil and low rainfall have made it an important crop in the semiarid regions across Africa and Asia. It requires very few inputs, ...

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

References

Bibliography

* 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. Minnesota University, USA. {{Clear Beneficial * * Beneficial weeds beneficial weeds