The research was conducted in 2011-2015 in Kirov region. Three-time cutting use of trefoil-timothy mix while harvesting at branching, bud formation and flowering stages of trefoil development had been planned. Possibility of durable (up to 5 years) growing of this grass mixture has been established. The productivity of lotus-timothy grass mixture depended largely on weather conditions. Under favorable weather conditions of 2012 the productivity of lotus-timothy grass mixture reached 115.4 GJ/ha; under dry conditions of 2013 it was lower than 41.8 GJ/ha. The best mode of grass mixture use is two-cutting at the first and the second hay cutting harvesting at lotus flowering stage when output of exchangeable energy equals to 65.3 GJ/ha in average for 2...5 years of life; as a variant - the first hay cutting - at flowering stage, the second one - at budding stage - 69.5 GJ/ha. Productivity of grass mixture was significantly lower at early harvesting of the first and the second hay cutting; the same is true for three-cutting use in some years. Meadow timothy as a moisture-loving crop fell out of the grass stand by the fourth year of life because of drought in all variants of the experiment. Infestation of crops with dandelion was marked since the fourth year of life in all variants of the experiment; its portion in the yield increased by the fifth year of life; the least infestation was noted in variants with two-cutting mode use.