A method of synthesizing ZSM-48 crystals, at least 25 vol% of the as-synthesized crystals having a fiber morphology, a needle-like morphology, or a combination thereof, the method comprising: crystallizing a reaction mixture comprising a source of water, a source of an oxide of a tetravalent element Y, a source of an oxide of a trivalent element X, a source of an alkali and/or alkaline earth metal, M, the alkali and/or alkaline earth metal being Li, K, Ca, Mg, or a combination thereof, and a source of a structure directing agent in the form of an organic cation, Q, having the structure R 1 -R 3 -R 2, the reaction mixture being substantially free of intentionally added sodium such that only incidental sodium from the sources in the reaction mixture are present and having a molar ratio of structure directing agent cation, Q, to oxide of tetravalent element Y in said reaction mixture from 0.01 to 0.05; a molar ratio of oxide of tetravalent element Y to oxide of trivalent element X in said reaction mixture from 50 to 120; a molar ratio of water to oxide of tetravalent element Y in said reaction mixture from 1 to 500; a molar ratio of hydroxyl group concentration to oxide of tetravalent element Y in said reaction mixture from 0.1 to 0.3; and a molar ratio of alkali and/or alkaline earth metal, M, to oxide of tetravalent element Y in said reaction mixture from 0.05 to 0.4, where R 1 and R 2 are the same or different, R 1 and R 2 representing tetraalkylammonium groups having the formula -N + -RR'R", where R, R', and R" are each the same or different, the R, R', and R" alkyl groups each being an alkyl group having from 1 to 10 carbons, where R 3 is a polymethylene group of formula (CH 2) n, where n = 6, where crystals having a L/D ratio of greater than 10/1 are of the fiber morphology and crystals having a L/D ratio from 2/1 to 10/1 are of the needle-like morphology, and where L represents the length and D represents the diameter. crystallizing a reaction mixture comprising a source of water, a source of an oxide of a tetravalent element Y, a source of an oxide of a trivalent element X, a source of an alkali and/or alkaline earth metal, M, the alkali and/or alkaline earth metal being Li, K, Ca, Mg, or a combination thereof, and a source of a structure directing agent in the form of an organic cation, Q, having the structure R 1 -R 3 -R 2, the reaction mixture being substantially free of intentionally added sodium such that only incidental sodium from the sources in the reaction mixture are present and having a molar ratio of structure directing agent cation, Q, to oxide of tetravalent element Y in said reaction mixture from 0.01 to 0.05; a molar ratio of oxide of tetravalent element Y to oxide of trivalent element X in said reaction mixture from 50 to 120; a molar ratio of water to oxide of tetravalent element Y in said reaction mixture from 1 to 500; a molar ratio of hydroxyl group concentration to oxide of tetravalent element Y in said reaction mixture from 0.1 to 0.3; and a molar ratio of alkali and/or alkaline earth metal, M, to oxide of tetravalent element Y in said reaction mixture from 0.05 to 0.4, where R 1 and R 2 are the same or different, R 1 and R 2 representing tetraalkylammonium groups having the formula -N + -RR'R", where R, R', and R" are each the same or different, the R, R', and R" alkyl groups each being an alkyl group having from 1 to 10 carbons, where R 3 is a polymethylene group of formula (CH 2) n, where n = 6, where crystals having a L/D ratio of greater than 10/1 are of the fiber morphology and crystals having a L/D ratio from 2/1 to 10/1 are of the needle-like morphology, and where L represents the length and D represents the diameter.