Determining the right time to harvest corn is very important. Existing systems for estimating the silage maturity of maize hybrids are very indicative. Maize can be easily ensiled, but the maximum yield of dry matter and nutrients can only be achieved with it if it is harvested at the right time and in the right way. The right time is when the whole plant has a dry matter content between 30 and 35% and there is still enough water soluble sugars (WSC) in the plant. Once the plant dry weight exceeds 30%, the WSC content drops dramatically and starch is rapidly formed in the grains. The ideal time to harvest occurs when the sum of WSC and starch content is highest. The excellent silageability of maize is maintained if anaerobic conditions are quickly created during harvesting and a low buffering capacity is maintained (no impurities get into the silage). Silage maturity dr. Mitrík recommends defining the calendar day on which the dry matter content of 30% is reached in whole plants. The optimal harvest time (harvest window) must be determined for individual hybrids on the basis of monitoring the development of the content of dry matter, water-soluble sugars and starch. Hybrids should be harvested gradually according to the silage maturity reached.