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Two experiments were conducted during which juvenile hardwood or softwood stem cuttings of loblolly pine (Pinus taeda L.) were rooted under six mist regimes in a polyethylene-covered greenhouse to investigate the effect of mist level on vapor pressure deficit (VPD) and cutting water potential (Ψ_cut), and to determine the relationships between these variables and rooting percentage. In addition, net photosynthesis at ambient conditions (A_ambient) and stomatal conductance (g_s) were measured in stem cuttings during adventitious root formation to determine their relationship to rooting percentage. Hardwood stem cuttings rooted ≥80% when mean daily VPD between 1000 and 1800 hr ranged from 0.60 to 0.85 kPa. Although rooting percentage was related to Ψ_cut, and A_ambient was related to Ψ_cut, rooting percentage of softwood stem cuttings was not related to A_ambient of stem cuttings. Using VPD as a control mechanism for mist application during adventitious rooting of stem cuttings of loblolly pine might increase rooting percentages across a variety of rooting environments.