New Zealand White Clover ( Trifolium repens ) is a perennial nitrogen fixing legume that reaches about 8-12 inches in height. New Zealand White Clover is more tolerant of heat and drought than larger clovers, is more vigorous, and tolerates a wide range of soils. New Zealand White Clover forms a symbiotic relationship with nitrogen fixing soil bacteria called Rhizobium trifolii . Rhizobium bacteria are found in root nodules of clover and other legumes. The Rhizobium bacteria fix atmospheric nitrogen into ammonium that the plant uses for growth and development. The plant in turn provides a suitable growth environment (root nodule) as well as other nutrients such as carbohydrates and protein. New Zealand White Clover is used as green manure as it fixes up to 170 pounds of nitrogen per acre. Excess nitrogen is released into the surrounding soil where associated plants use it for growth and development. Local Orchards, Valencia County Extension Service, and Homeowners use New