Trifolium repens L.

White Clover
Symbol: 
TRRE3
Group: 
Dicot
Family: 
Fabaceae
Uses: 
Beautification
Grazing
Hay
Pasture
Pollinators
Silage
Soil Improvement (Green manure)
Soil Protection (Cover Crop)

White clover is a cool season, perennial legume. It is extensively used in grass-legume pastures in humid, temperature climates. Plants are glabrous with indeterminate, prostrate stolons that root at nodes. Leaves are palmately trifoliate with long petioles. White to pinkish flowers are borne in round heads on long peduncles. Moderate to high fertility and adequate moisture are needed for good white clover production. White clover is tolerant of moderately acid to moderately alkaline soils, wet soils, and flooding. It does not grow well under saline conditions or heat and drought. It is typically grown in combination with cool-season grasses. Continual haying will cause a loss of white clover in the stand due to shading from tall grasses. Continued close grazing will favor the clover over pasture grasses. White clover is susceptible to slug damage and has a higher risk of causing bloat than other clovers. Varieties may be grouped into small (common or wild), intermediate ('Dutch' and 'New Zealand'), and giant (ladino) types, with varied pest resistance.

Identification

Type: 
Legume
Life cycle: 
Long-lived perennial
Growth Season: 
Cool
Identification Characteristics: 

Image Gallery: The OSU Forage Information System contains an Image Gallery that includes White Clover photographs and drawings useful in identification.

The URL for the gallery is:  http://forages.oregonstate.edu/image-gallery

The direct URL for White Clover is: 

Inflorescence: The white clover inflorescence is a globose (spherical) head (umbel), borne on long peduncles with 20-100 florets. White clover inflorescence image.

Flowers: White to pinkish florets with short stalks. White clover florets image.

Seed: Seeds are small (1.1-1.2 mm long, 0.9-1.0 mm wide) with 800,000 seeds/lb (1,764,000 seeds/kg). They are heart-shaped [round to ovate (egg-shaped), triangular, or oval] and their surface is smooth, with a yellowish to reddish color. White clover seed image.

Stems:  White clover is stoloniferous; these glabrous (hairless) horizontal stems grow close to the soil surface and root at the nodes. White clover stem image.

Leaves: Palmately trifoliate leaves are borne on long, glabrous petioles. Leaflets are oblong to wedge-shaped, serrated around the margin, usually with v-shaped white marks (known as a "water marks"). Leaflets may also have various red pigment flecks. White clover leaf image.

Stipules: Stipules are membranous, oblong to lanceolate. White clover stipules image.

Roots: White clover is shallow-rooted, with most found within the top 8 inches (20 cm) of soil. The short taproot that is produced during the initial weeks after germination decays after the first year. Adventitious roots develop at the nodes of stolons. White clover root image.

Other Sources for White Clover Images:

Growth Habit and Production

Growth Habit and Persistence: 

White clover types display varying degrees of prostrate growth, as it spreads by stolons. Small (wild) types have very short, prostrate growth. Medium ('New Zealand' and 'Dutch') types are larger. Large ('Ladino') types have very large leaves and longer petioles, making them more suitable for haying systems.

Invasive potential:

White clover’s invasive potential is consider to be medium, since it spreads vigorously by stolons and reseeds naturally if allowed to mature. Since it is indeterminate and seed heads are held close to the ground, much viable seed is produced yearly that escapes harvest. These seeds are disseminated by wind, water, birds, and grazing animals. In wet years, it may spontaneously appear in early spring in thin plant stands or on bare soil where suppression is weak or absent. It is often considered a weed in lawns where a grass monoculture is desired. However, it is easily eliminated by using a broadleaf herbicide. In addition, white clover can be readily reduced in stands through competition from other, taller growing plants, especially as soil nitrogen status improves.

Persistence:

Persistence of white clover is considered to be medium; its short taproot decays after the first year, with its regenerative potential through its stolon growth, rooting at the nodes. Stand longevity is promoted from this asexual propagation or reseeding. White clover is susceptible to many viral diseases which reduce its vigor and result in death from secondary causes. Partial or complete stand loss also can occur from root diseases and root-knot nematodes. White clover is known for dramatic cycles in population. It is highly susceptible to drought, most often the cause of substantial stand losses.

 

Production Profile: 

Physiology and growth period:

White clover is a cool-season legume with C3 physiology. Its growth initiates at 50 °F (10 °C) and stops at 86 °F (30 °C). Optimal growth occurs within the range of 68 to 71 °F (20-22 °C). As a legume, it is able to fix atmospheric nitrogen (N2) for its own growth and associated grasses.

 

Climate and Soil Suitability Zones

Suitability zones:

White clover is best suited to humid, temperate climate regions of the world. It is cold tolerant but has a low tolerance to heat and drought. Thus, although it grows well on soils that are well to poorly drained, it requires irrigation in low soil moisture conditions.  It tolerates acid to moderately alkaline soil conditions.

It is grown throughout the humid region of the USA and the irrigated west and similar areas worldwide. Distribution extends from the Arctic regions of Russia and Canada to the subtropical areas of Australia and South America.

Tolerances:

Quantitative Table:

 

1For the High values for January Minimum temperature and Annual Precipitation, 9999 indicates no upper limit.
2For Soil Drainage categories, abbreviations are used for Soil Drainage categories: VPD (very poorly drained), PD (poorly drained), SPD (somewhat poorly drained), MWD (moderately well drained), WD (well drained), SED (somewhat excessively drained), ED (excessively drained).

 

Fertility: White clover is best adapted to fertile soil conditions. It needs a good soil P and K status, but moderate soil N level (high soil N levels will inhibit nodulation). Sowing (or oversowing) after the removal of a silage crop, which will have removed much of the available soil N, is one option. Inoculate seed with the appropriate <i>Rhizobium</i> culture immediately before planting.

Quantitative Table:

 

July 
Max Temp (°C)

Jan 
Min Temp (°C)

Annual 
Precip (mm)

Soil pH

Soil Drainage
(categories)

Soil Salinity
(mmhos/cm)

 

Low

High

Low

High

Low

High

Low

High

Low

High

Low

High

Well Adapted

20

32

-10

9999

650

9999

5.5

7.5

MWD

SPD

0

2

Moderate

18

32.5

-13

9999

550

9999

5.0

8.0

SPD

WD

0

4

Marginal

16

33.5

-16

9999

450

9999

5.0

8.5

PD

WD

0

6

1For the High values for January Minimum temperature and Annual Precipitation, 9999 indicates no upper limit.
2For Soil Drainage categories, abbreviations are used for Soil Drainage categories: VPD (very poorly drained), PD (poorly drained), SPD (somewhat poorly drained), MWD (moderately well drained), WD (well drained), SED (somewhat excessively drained), ED (excessively drained).

Quality and Antiquality Factors

Quality Factors: 

White clover is known for its excellent forage quality, being high in protein and digestibility.

Anti-quality Factors: 

White clover has a high bloat potential when grown alone, therefore in pastures it usually is grown in mixtures with one or more grasses.

Cultivars

Three types of white clovers are recognized: small, intermediate, and large.

  • Small types persist well due to their prostrate growth habit.   'Kent Wild White' is an example cultivar.
  • Intermediate types flower more profusely than large types, allowing them to be used as reseeding winter annuals in southeastern US pastures. Example cultivars include 'Common', 'White Dutch', and 'New Zealand'.
  • Large types have the largest petioles, leaflets, and stolons and produce the most forage, especially under rotational grazing or mechanical harvesting systems. The name Ladino was derived from the ecotype name "Ladino Gigante Lodigiano." Although this is now used to describe all large-type white clovers, it is incorrect since large-type white clovers are now quite different from the original Italian ecotype. 'Regal' and 'Osceola' are examples of large-type white clover cultivars.

USDA National Plant Germplasm System (Crop Science Registrations)

Institute of Grassland and Environmental Research (white clover breeding program and cultivar descriptions); https://www.aber.ac.uk/en/media/departmental/ibers/pdf/innovations/01/chapter_4.pdf

Nobel Foundation Forage Improvement Division

Image Gallery

Resources

Publications: 

Aberystwyth University IBERS - http://www.rwn.org.uk/aber-clover-management-guide.pdf; http://beefandlamb.ahdb.org.uk/wp/wp-content/uploads/2016/07/BRP-Managin...

Clemson University - http://www.clemson.edu/extension/hgic/pests/weeds/hgic2324.html

Cornell - http://covercrops.cals.cornell.edu/white-clover.php

Oregon Clover Commission - http://www.oregonclover.org/clovers/whiteclover/

Oregon State University

Penn State University - http://extension.psu.edu/plants/crops/forages/species/white-clover

SARE - http://www.sare.org/Learning-Center/Books/Managing-Cover-Crops-Profitabl...

Teagasc - http://orgprints.org/28971/1/White%20Clover%20leaflet%20final.pdf

Texas A&M University - http://aggieclover.tamu.edu/planting_guide/white/

University of California IPM - http://ipm.ucanr.edu/PMG/WEEDS/white_clover.html

University of Florida - http://edis.ifas.ufl.edu/aa198

University of Georgia - http://extension.uga.edu/publications/detail.cfm?number=B1251; http://georgiaforages.caes.uga.edu/species/WhiteClover.html

University of Hawaii - http://www.ctahr.hawaii.edu/oc/freepubs/pdf/CoverCrops/whiteclover.pdf

University of Kentucky - http://www.uky.edu/Ag/CCD/introsheets/clover.pdf

University of Missouri - http://extension.missouri.edu/p/G4639

USDA NRCS Fact Sheet - https://plants.usda.gov/factsheet/pdf/fs_trre3.pdf

Virginia Tech - https://oak.ppws.vt.edu/~flessner/weedguide/trfre.htm