Common Name: Persian Clover

General Information

Trifolium resupinatum is an erect decumbent or prostrate, coarse, annual to biennial plant, branching from the base and growing 15 - 30cm tall, though prostrate forms can have stems 50 - 100cm long[, ].
The plant is sometimes harvested as a food, especially in Asia, and is also widely grown as a green manure, forage and bee crop. It is cultivated in ornamental gardens, valued especially for its sweet-smelling flowers.

Known Hazards

None known

Botanical References

Range

Eurasia - - France to Portuga, east to southern Siberia, Afghanistan, Pakistan, Turkey and the Levant; N. Africa - Morocco tp Egypt

Habitat

Found mostly on heavy soils, growing on fallows and in natural grazing, on roadsides and waste ground[]. Roadsides, in fields, waste places, humid grassy plains and lower mountains; at elevations from sea level to 1,500 metres[].

Properties

Edibility Rating
Other Uses Rating
Habit	Annual/Biennial
Height	0.25 m
Pollinators	Bees, Insects
Self-fertile	No
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Trifolium resupinatum is a plant of the temperate to subtropical zones, growing at elevations up to 1,500 metres. It grows best in areas where annual daytime temperatures are within the range 13 - 22°c, but can tolerate 3 - 26°c[]. When dormant, the plant can survive temperatures down to about -12°c, but young growth can be severely damaged at -1°c[]. It prefers a mean annual rainfall in the range 600 - 900mm, but tolerates 300 - 1,360mm[].
Grows best in a sunny position but toleratis light shade[]. Prefers a heavy soil but succeeds in a wide range of soils[, ]. Thrives on wet, heavy soils in low areas[]. Tolerant of moderately saline soils[]. Prefers a pH in the range 6 - 7, tolerating 4.8 - 8.2[].
The plant has been widely grown as a forage and green manure crop, especially in Asia, though cultivation has also spread to America, Europe, northern Africa and Australia. Cultivars had been released in European countries, the USA and Australia.
When sown in the autumn in mild winter areas the plant can produce a good bulk of green manure by early spring, flowering in mid spring and fruiting in late spring[].
Recorded green manure yields are about 40 tonnes per hectare, whilst seed yields are from 150 - 300 kilos per hectare[].
The species is very variable: var. minus Boiss., is the wild form, whilst the cultivated ones are var. resupinatum and especially var. majus Boiss.[].
The plant has pink-mauve, sweet-smelling flowers, ovoid pods and pale brown seeds[].
This species has a symbiotic relationship with certain soil bacteria; these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

Leaves and young stems - cooked and eaten as a vegetable[].

Medicinal

None known

Agroforestry Uses:

The plant is grown for forage, hay and green manurel[]. When used as a green manure, it is often planted before cotton[]. It can be mixed with Phacelia tanacetifolia when being grown as a green manure[].

Other Uses

None known

Propagation

Seed - the seed of Trifolium species is often of two kinds - hard-coated and soft-coated. The soft-coated seeds can germinate immediately, whilst hard-coated seeds remain dormant until the seedcoat has broken down enough to permit the ingress of water. In order to speed up and improve germination rates, hard-coated seeds benefit from scarification before sowing. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing. The seed can usually be sown in spring in situ.
If the seed is in short supply, it might be better to sow it in pots in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and plant them out after the last expected frosts.