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Organic Farming: Which Green Manure Should I Grow? - Table of Crops

Note Number: AG1122
Published: December 2007
Updated: September 2010


Green manure/Cover crop

For explanations of column headings, refer to the main page. 


Green manure/over crop annual/peren-nial (a),(p) Scientific name Best sowing time Root system Avg Biomass t/ha & avg kg N/ha Weeds, pests and diseases suppressed, (incl. allelopathy) Host of these vegetable diseases Host of these vegetable pests Host/habitat for these beneficial insects Can be sown in combination with Other features
Birdsfoot Trefoil p Lotus corniculatus autumn, spring highly branched 30-60 cm depth 8 t/ha; 30-180 kg N/ha (nitrogen per ha)     native budworm (Helicoverpa punctigera (previously Heliothis punctigera)), root-knot nematodes Meloidogyne javanica, M. hapla, cyst nematodes (Heterodera spp), root-lesion nematodes (Pratylenchus spp.) minute pirate bug (Orius tristicolor) slow-growing grasses tolerates droughty and waterlogged soils; contains tannin, which, when grazed, reduces need for drenching lambs; slow regrowth after slashing
Biserrula a Biserrula pelecinus autumn deep (0.70-1.2 m) 4-7 t/ha     lucerne flea, vegetable weevil, jassids, Helicoverpa spp., aphids; has some tolerance of red legged earth mite, blue oat mite   sub-clover, Serradella best on acidic sandy soils
Clovers   Trifolium spp.   taproot with spreading branched laterals; rhizomes; stolons 4 - 10 t/ha generally weed suppressing when fully established; fast initial growth is important Pythium spp.; Sclerotinia spp. species dependent most nematode species: Meloidogyne spp., Xiphinema spp., stem & bulb nematode (Ditylenchus dipsaci), Tylenchorhynchus spp., red legged earthmite, lucerne flea, cowpea aphid, alfalfa aphid generally pollen and nectar food for beneficial insects; lacewings, spiders    
Arrowleaf clover a Trifolium vesiculosum early autumn to mid-winter deep 5.5-11 t/ha   Rhizoctonia solani; but no significant diseases recorded in Australia red legged earth mite, lucerne flea at seedling stage, Meloidogyne graminicola, M. incognita   annual grasses resistant to bean yellow mosaic virus; intolerant of alkaline soil
Balansa clover a Trifolium michelianum early autumn extensive 5-6 t/ha dryland; 7-8 t/ha under irrigation tolerant of red legged earth mite when mature Pythium spat seedling stage; alfalfa mosaic virus red legged earth mite, lucerne flea, lucerne aphid at seedling stage, Meloidogyne graminicola, M. incognita   Persian clover, sub-clovers, salt tolerant grasses, tall wheat grass, annual & perennial clovers, annual grasses, lucerne, ryegrass moderately tolerant of salt, water logged soils and drought
Berseem clover a Trifolium alexandrinum early autumn up to 60 cm 10 t/ha early vigorous establishment needed for weed suppression; does not suppress fathen (Chenpodium album) and mallow (Malva sp.) cucumber mosaic virus plant parasitic nematodes in limited numbers, esp. Meloidogyne spp., incl. M. javanica bees & other pollinating insects; nectar food for many insects white clover, oat, cereal rye, annual rye grass  
Crimson clover a Trifolium incarnatum late summer,early autumn deep taproot 5-8 t/ha; 54-85 kg N/ha less weed suppressing than more prostrate clovers Pythium sp, Rhizoctonia sp. blue-green aphid, pea aphid, thrips, several nematode species incl. Meloidogyne hapla and M. arenaria bees, ladybirds, bigeyed bug (Geocoris sp), minute pirate bug cocksfoot, white & sub-clover, burr medic, cereal grains, vetches, annual ryegrass, tall fescue decomposes rapidly, when incorporated; higher water use efficiency than hairy vetch
Persian (Shaftal) clover a Trifolium resupinatum late summer to autumn dense 8-15 t/ha; 85-160 kg N/ha quick ground cover for weed suppression   red legged earth mite, lucerne flea, Meloidogyne spp., incl. M. javanica bees & other pollinating insects; nectar food for many insects tall wheat grass in waterlogged areas; other clovers tolerates medium salty and waterlogged soils; excellent regrowth after slashing
Green manure/over crop annual/peren-nial (a),(p) Scientific name Best sowing time Root system Avg Biomass t/ha & avg kg N/ha Weeds, pests and diseases suppressed, (incl. allelopathy) Host of these vegetable diseases Host of these vegetable pests Host/habitat for these beneficial insects Can be sown in combination with Other features
Red clover short lived p; a Trifolium pratense early autumn taproot to 90 cm, spreading branched laterals in top 12 cm 5.5 t/ha; 1.6-2.2 t/ha dry matter; 50 kg N/ha allelopathic effect against wild mustard; suppresses weeds Fusarium wilt(Fusarium oxysporum), common peamosaic virus, cucumber mosaic virus, alfalfa mosaic virus, Sclerotium rolfsii root knot nematodes Meloidogyne spp., incl. M. javanica and M. hapla, root lesion nematodes., cyst nematodes ladybirds, hoverfly, lacewings, wasps can be inter-planted into short crops only some varieties tolerate waterlogged soils; some varieties resistant to Sclerotinia crown rot
Rose clover a Trifolium hirtum autumn taproot up to 2 m 7 t/ha; 75 kg N/ha     nematodes Meloidogyne incognita & M. javanica minute pirate bug sub-clover, barrel medic, lucerne, perennial grasses drought tolerant
Strawberry clover p Trifolium fragiferum spring taproot to 1m, in wet and saline soils the roots remain in the top 8-10 cm 3.7-11 t/ha; 40-330 kg N/ha vigorous stand has a low, thick weed smothering growth habit Sclerotinia sp. red legged earth mite, blue oat mite, stem & bulb nematode, cyst nematode,root-knot nematodes Meloidogyne hapla, M. javanica, but not good host for M. incognita and M. arenaria beneficial insect attractor tall wheat grass, Puccinellia, white clover, perennial rye grass, phalaris, tall fescue tolerates waterlogged soils & medium saline soils; medium drought resistance
Sub-clovers a Trifolium subterraneum autumn taproot with fibrous supporting roots 3.3-9.5 t/ha; 100-225 kg N/ha smothers weeds generally; St. John's Wort (Hypericum perforatum) Fusarium sp., Rhizoctonia sp., Aphanomyces sp., red leaf virus several plant parasitic nematode species ladybirds, bigeyed bug medics, annual and perennial grasses, lucerne tolerates temporary flooding, drought; can be serious weed in annual vegetables; loosens compacted soil
Sweet clovers a; bi-ennual Melilotus spp. autumn strong taproot 2.5-9 t/ha suppresses weeds due to quick growth; nematodes   several plant parasitic nematode species bees, large predatory wasps, Tachinid flies tall wheat grass; cereals tolerates salinity & water logging; some varieties toxic to livestock; drought resistant; alleviates soil compaction
White sweet clover   Mellilotus alba autumn deep taproot   may suppress Sclerotium rolfsii, if incorporated into the soil   Meloidogyne hapla, M. incognita, M. javanica, cyst nematode. blossoms attract bees, Tachinid flies, large predatory wasps   poor competitor, especially during establishment; excellent at loosening topsoil and subsoil, and releasing P and K; drought tolerant once established
Yellow sweet clover   Melilotus indica or M. parviflorus or M. officinalis autumn         Meloidogyne hapla, cyst nematode.      
White clover p Trifolium repens autumn shallow, most roots to 20 cm; stolons; taproot may reach 90 cm 12-25 t/ha; 1.6-3.5 t/ha dry matter; 40-270 kg N/ha smothers weeds; may reduce thrips and brassica pests when intercropped Pseudomonas syringae, Sclerotium rolfsii, Rhzoctonia sp., Fusarium sp., Anthracnose (Colletotrichum sp.) many arthropods, mites, many plant parasitic nematode species, Western Flower Thrip, spider mite bees, aphidophagous (aphid eating) insects (hover flies, lacewings, predatory midge, predatory myrid, lady beetles) other clovers, medics, grasses, but grasses difficult to maintain  



Vigna unguiculata

late spring, summer

strong taproot, laterals near surface

4-5 t/ha; 2.2 t/ha dry matter; 70-350 kg N/ha

suppresses weeds through vigorous growth; suppressed Meloidogyne arenaria, M. incognita, Heterdodera glycine in green house experiment

Fusarium wilt, Rhizoctonia solani

cowpea aphid; Meloidogyne spp, leafminers, leafhoppers, mites, thrips, aphids

bees, ladybirds, predatory wasps, ants, soft-winged flower beetle

Japanese millet, sorghum, soybean, peanut

warm climate crop, suitable only for the north region of Victoria; moderately drought resistant because taproot draws moisture from deep in the soil profile



Trigonella foenum-graecum


deep taproot

1.5 t/ha dry matter



Rhizoctonia solani, Fusarium Wilt, Meloidogyne incognita, M. javanica


field bean, cereals (barley)

some drought and salt tolerance

Faba bean


Vicia faba


taproot; strong root system

5.5-9 t/ha; 22-90 kg N/ha



root knot nematodes Meloidogyne spp; bean aphid

extra-floral nectar source from early vegetative growth to late pod filling


break crop for fields with Sclerotinia minor; does not respond to mowing or grazing

Field pea


Pisum sativum

(early) autumn


6.5-9.5 t/ha; 3 t/ha dry matter; 30-140 kg N/ha


Fusarium wilt, Aphanomyces sp., Sclerotinia sp.

aphids, plant parasitic nematodes

aphid predators, eg. 7-spotted ladybird (Coccinella septempunctata), Syrphid flies; bees, native pollinators

cereals (usually oats, but also rye, barley, wheat); brassicas

on its own not vigorous enough to suppress weeds

Lucerne or alfalfa


Medicago sativa

late summer, spring

deep taproot

8 t/ha dry matter

clover seed; Sclerotium rolfsii

Alfalfa mosaic virus

Pratylenchus penetras , P. neglectus, Meloidogyne arenaria, M. hapla, M. incognita, M. javanica

food & shelter for beneficial insects; assassin bug, minute pirate bug


there are winter active and winter dormant lucerne varieties



Lupinus spp.

early autumn

strong deep taproot

10 t/ha; 60-350 kg N/ha, varieties differ


Sclerotinia sp.,cucmber mosaic virus, Rhizoctonia sp., Anthracnose sp., bean yellow mosaic virus

red legged earth mite, native budworm, several cyst nematode and root knot nematode species; thrips

ladybirds; bees; important honey plant;


species vary in pH preference; alkaline tolerant species do not like free lime; iron deficiency on calcareous soil



Medicago spp.

autumn; (early spring)


8 t/ha; 1.5-2.5 t/ha dry matter; 55 - 220 kg N/ha



red legged earth mite, root lesion nematode species

lacewings, hoverflies


deeper rooted and more drought tolerant than sub-clovers; different species and varieties with different characteristics for various growing conditions and pest and disease resistance or susceptibility

Barrel medic a

Medicago truncatula






red legged earthmite; blue oat mite, springtails or lucerne flea; pea aphid; Meloidogyne. hapla


sub-clovers; lucerne


Gama medic a

Medicago rugosa






red legged earth mite; Sitona weevil (Sitona humeralis)




Snail medic a

Medicago scutellata






red legged earth mite, blue oat mite, springtails or lucerne flea; pea aphid




Strand medic a

Medicao littoralis






red legged earth mite, blue oat mite, springtails or lucerne flea; pea aphid




Green manure/over crop annual/peren-nial (a),(p) Scientific name Best sowing time Root system Avg Biomass t/ha & avg kg N/ha Weeds, pests and diseases suppressed, (incl. allelopathy) Host of these vegetable diseases Host of these vegetable pests Host/habitat for these beneficial insects Can be sown in combination with Other features

Mung bean


Vigna radiata

late spring, summer




as other legumes, esp. cowpea, since cowpea and mung bean are related

Helicoverpa punctigera, green vegetable bug; green mirids; thrips



warm climate crop, suitable only for northwest region of Victoria



Ornithopus spp

autumn, (winter)


3-6 t/ha


Rhizoctonia sp., Anthracnose sp.

Helicoverpa punctigera


ryegrass, fescue; clovers, Biserrula

varietal difference in relation to growing conditions; tolerates acidic soils; not suited for heavy clay soils and very alkaline soils

Soybean, trailing


Glycine soya or G. max



4 t/ha

weed suppressing



insect attraction

millet, cowpea, sweet corn




Vicia spp.

early autumn, spring, summer



possibly lettuce


nematode species

ladybirds, bigeyed bug



Hairy vetch a

Vicia villosa

early autumn, spring, summer

taproot 30-90 cm

4.8-7.8 t/ha; 2.2-5.6 t/ha dry matter; 90-150 kgN/ha



flower thrips (Frankinella spp), many nematode species, aphids, two-spotted spider mite

aphid predators, minute pirate bug; bigeyed bug, soil arthropods

wheat, oats, cereal rye, barley

toxic to cattle; nematode resistant; more winter hardy than common vetch; high water use efficiency

Purple vetch a

Vicia. atropurpurea, (the old name V benghalensis was still found in the literature)

spring to summer


4.8-7.8 t/ha; 2.2-5.6 t/ha dry matter; 55-225 kg N/ha

suppresses weeds, especially star thistle


Two-spotted mite; cyst nematode species, Pratylenchus vulnus; possibly Meloidogyne javanica

bees, many beneficial insects (assassin bug Apiomerus spp., minute pirate bug., lacewings, ladybirds)



Woolly Pod vetch a

Vicia benghalensis

early autumn

taproot to 80 cm

6.5 t/ha

weed smothering

major host for Sclerotinia minor



cereals, especially oats

toxic to cattle

Other broadleaf crops



Brassica spp.




soil pathogens: fungi and nematodes; also spiny sowthistle (Sonchus asper), scentless camomille (Matricaria sp.), amaranth (Amaranthus sp.), barnyard grass (Echinocloa crusgalli), meadow foxtail (Alopecurus sp.), wheat

clubroot (Plasmodiophora brassicae), downy mildew (Peronospora parasitica)

aphids, caterpillars, snails, slugs



Brassicas can be grown for biofumigation; brassica crops vary in content and type of glucosinolates and hence biofumigant effectiveness; does not host the very important vesicular-aruscular mycorrhyzal (VAM) soil fungi

Canola or rape


Brassica napus


deep taproot

5.5-7 t/ha 3.3 t/ha dry matter

spiral nematode (Rotylenchus reniformis )

Rhizoctonia sp., Sclerotinia sclerotiorum

nematodes, cabbage moth (Plutella xylostella)



organic and biodynamic growers be aware of GMO status

Yellow or White mustard


Sinapis alba or Brassica alba or B. hirta

spring to early autumn



nematodes; some potential to reduce wireworm and slugs; allelopathic effect against weeds

Rhizoctonia sp., clubroot(Plasmodiophora brassicae)

turnip aphid (Hyadaphis erysimi), cabbage aphid (Brevicoryne brassicae), thrips

ladybirds, hoverflies



Indian mustard


Brassica juncea

spring to early autumn


5.5-9.5 t/ha dry matter







Fodder brassicas





10-15 t/ha dry matter









Fagopyrum esculentum


short taproot with fibrous laterals, top 25 cm

1-1.5 t/ha

smothers weeds

Rhizoctonia solani

root lesion nematode

hoverflies; nectar seeking insects


cool climate; short season (matures in 8-10 weeks) summer crop; extracts phosphorus in low phosphorous soils; honey crop



Linum usitatissimum





Fusarium wilt, Rhizoctonia solani

Helicoverpa punctigera, root-lesion nematode spp., Meloiodogyne artiellia, M. incognita



Fusarium resistant varieties exist; break crop as hardly any disease problems; trap crop for Orobanche sp. (broomrape); needs presence of vesicular arbuscular mycorrhizae (VAM) for efficient phosphorus uptake



Helianthus annuus

spring to summer

strong taproot, lateral branches

4-5 t/ha dry matter

nematodes; sweet corn (Zea mays), sorghum (Sorghum vulgare), Guar (Cyamopsis tetragonoloba)

Sclerotinia sclerotiorum

Helicoverpa spp., several plant parasitic nematode species

arbuscular mycorrhizae (AM)





Tagetes minuta

spring to summer









Cereals and Grasses



Hordeum vulgare

late summer, autumn, early spring

strong, fibrous

7.5-17.5 t/ha; more than oat, cereal rye, wheat

flailed barley inhibits cereal rye; strong tillering at base, hence better weed control than oats; rye, wheat


host for nematode Meladoigyne javanica; minor host for M. arenaria

damsel bug, (Nabidae sp.), Encyrtidae parasitoid of cutworm larvae

brome, cereal rye, annual clovers, medics, vetch; pea, barley, white mustard




Avena sativa



9-13 t/ha

non- or poor host to nematode Meloidogyne hapla and M. javanica


several plant parasitic nematode species


cereal rye, which increases mycorrhizal colonisation


Cereal rye


Secale cereale


fibrous; stronger than other cereals

4.5-11 t/ha

rye residues on the surface suppress: sweet corn, weeds (pigweed, barnyard grass, fathen (Chenopodium album); non- or poor host to nematode M. hapla, Pythium spp.


nematodes Ditylenchus dipsaci, Heterodera avenae, Aphelenchus tritici, Meloidogyne arenaria, M. javanica


Berseem clover, oats

drought resistant



Triticum spp



4-9.5 t/ha

stem & leaf residues suppressed annual ryegrass (Lolium rigidum) in laboratory trial; cultivar dependent

Cavity spot (Pythium violae)

several plant parasitic nematode species

damsel bug, (Nabidae sp.), Encyrtidae parasitoid of cutworm larvae


Cavity spot (Pythium violae) is a widespread carrot disease in Northern Victoria and South Australia

Japanese millet


Echinochloa utilis or E. crusgalli

spring, summer

fibrous, mainly top soil

up to 35 t/ha; 4-7t/ha dry matter

weed smothering; nematode Paratylenchus projectus


Meloidogyne arenaria, M.incognita, M. javanica


soybean; cowpea

more cold tolerant than Siberian millet

Siberian or White Panicum millet


Echinocloa frumentacea

spring, summer

fibrous, mainly top soil

up to 35 t/ha; 4-7 t/ha dry matter

weed smothering through prostrate growth





optimum temperature 25-30°C; grows more slowly than Japanese millet; better regrowth after grazing or slashing

Forage (Pearl) millet


Pennisetum sp.

spring, summer

larger and deeper than Japanese millet


suppresses weeds through vigour


several plant parasitic nematode species



growth habit similar to sorghum



Puccinellia ciliata

autum, late winter, early spring







tall wheat grass, strawberry clover

main use for reclamation and ground cover on very saline & waterlogged soils

Sorghum/ Sudan grass


Sorghum vulgare

spring, summer


16-22 t/ha

wheat; nematodes Meloidogyne hapla; weeds


several plant parasitic nematode species, corn aphid



needs N fertilisation after cutting

Tall wheat grass


Thinopyron ponticum

winter to spring







Puccinellia, tall fescue, phalaris, strawberry clover, white clover, Balansa clover

used for reclamation and as ground cover of saline and water logged soils


a; p







slugs, snails,red legged earth mite, blue oat mite




Annual ryegrass


Lolium rigidum

early autumn

extensive, shallow







will become a weed, if let go to seed

Perennial ryegrass


Lolium perenne

autumn to early spring

extensive, shallow


clovers; allelopathic effect against weeds




Legumes (white, red, subterranean clovers, lucerne), temperate grasses (fescue, cocksfoot, phalaris)