White Clover

General Description

White clover requires adequate growing season moisture and moderate summer temperatures. White clover is widely distributed, especially in cool temperate climates. The plant has stolons or creeping stems near the soil surface. Leaves, flowers, and roots grow directly from these stolons. It is a relatively short plant with indeterminate growth, although taller types can grow up to 25 cm (10 in).

There are three types of white clover which vary mostly in height and persistence. The small type is commonly found in lawn mixes, or naturalized in disturbed or heavily grazed moist areas. It is highly persistent. The large type, often called Ladino, is larger (four-times) than the small type. With its low persistence it is rarely used, but can be seeded for short term hayland especially under irrigation. The intermediate type, also called common or Dutch, yields well,  is a prolific seed producer, and is often used in for pasture in high moisture regions. 

White clover has 3 leaflets attached at a single point, and are dark green, often with a white watermark. Leaflets are finely toothed, hairless, and nearly round, up to 3 cm (1 1/4 in) wide. Plants are only as high as the length of the flower and leaf stocks, which varies by type from ground level 25 cm (10 in). Seedling plants develop a taproot initially and then as plants age they develop threadlike, fibrous roots growing from detached stolons. White clover can cause bloat.

Type

Agronomic legume.

Origin

Mediterranean origins. Brought to North America by settlers.

Longevity

At least 10 years. Stolon survival and self-seeding (seed set) is critical for persistence.

Use

Intermediate types used for pasture. Small types tend to increase in continually grazed pastures.

Optimal Time of Use

Summer, fall. Late spring, once the plant has reached full height and leaf canopy it is safe to begin use. 

Recovery After Use

Requires a minimum 30-45 days of recovery after use. Tolerates frequent grazing and can be grazed repeatedly throughout the season to 5 cm (2 inch) height. Intermediate and large types benefit from rotational grazing. Low growing points make small type white clover well adapted to use in continuous, closely grazed systems. Only graze lightly in the last six weeks of the growing season for improved winter survival.

Palatability/Nutritional Value

Excellent palatability, highly digestible. White clover crude protein is approximately 19.5-21% and total digestible nutrients is around 65%. Quality is maintained throughout the growing season as new leaves are grown. Can cause bloat. Sheep may select for white clover increasing their risk for bloat.

Annual Precipitation min/max (mm)

400mm / 1770mm

Drought Tolerance

Poor tolerance. White clover is unproductive even in short duration drought. It easily dies from long or extreme drought. Small types tend to be more drought tolerant.

Flooding Tolerance

Tolerates 1-2 weeks of spring flooding. High moisture is desired over the growing season, but flooding or water logging is not tolerated.

Winter Hardiness

Poor to fair hardiness. Growing points are in the stolons which are at or on the soil surface so very susceptible to winter kill. Maintaining soil fertility and restricting grazing to light or no grazing in the last six weeks of the growing season improves winter survivability. Intermediate and small types have some winter hardiness while large types are the least winter hardy.

Soil Texture Preference

White clover prefers fertile clay and loam textured soil. White clover may grow on coarser sandier soils if moisture is adequate.

Erosion Control

Not well suited. White clover may be included in some erosion control mixtures as a nitrogen fixer for grasses or as a plant for higher moisture areas. 

Salinity Tolerance

Not tolerant.

Acidity Tolerance

Moderate tolerance. White clover can grow in pH 5.0, but prefers 6.0 to 6.5.

Alkalinity Tolerance

Low tolerance.

Seeds per kg

1,764,000seeds/kg (800,000 seeds/lb)

Suggested Mixtures

White clover mixes well with most cool season perennial grasses, particularly bunch grasses that can tolerate frequent grazing allowing for an open canopy; meadow bromegrass, orchard grass, tall fescue. Has also been grown with Russian wildrye and timothy. White clover can compete with sod forming grasses such as Kentucky bluegrass, and smooth bromegrass when moisture and fertility are not limiting and frequent defoliation keeps the canopy open.

Ease of Establishment

White clover should be seeded shallow (6 mm / 0.25 in). Although seedlings are small and slow to develop, they can establish easily if fertility and moisture conditions are favourable. Competition from grasses and cover crops should be minimized. Stand will thicken as stolons develop.

Competitiveness

Small volunteer types can invade continuously grazed pastures, especially under moist conditions. Healthy stolons are critical for competitiveness. Shading of white clover decreases its competitiveness.

Management Considerations

It is important to monitor livestock for bloat while grazing white clover. Inoculate white clover with Rhizobium trifolii for better nodulation and nitrogen fixing. Grows best on fertile, moist soils without shading from other plants. Stolon survival is critical for persistence so maintaining adequate fertility is important. Although white clover can tolerate a shorter rest period than most other legumes in a grazing system, grazing should be light enough not to damage stolons. Restrict or reduce grazing in the last six weeks of the growing season to restore stolon health and provide a canopy to help insulate stolons for winter. White clover can be grazed after a killing frost, however, reducing the canopy increases the risk of winter kill.