A ground flare for burning of waste gas is disclosed having groups of burners in a pit for selective utilization in accordance with the quantity of gas to be burned together with controls therefor, and with provisions for reducing expansion of the headers carrying the gas. The burners are in groups, the burners in each succeeding group being in a predetermined increasing number to provide great variability in capacity of gas to be burned and with the burners being utilized more effectively than heretofore upon variation in the quantity of the waste gas delivered to be burned.