Plume-SPH provides the first particle-based simulation of volcanic plumes. Smooth particle hydrodynamics used here has several advantages over mesh-based methods for multiphase free boundary flows like volcanic plumes. This tool will provide more accurate eruption source terms to users of volcanic ash transport and dispersion models, greatly improving volcanic ash forecasts. The Plume-SPH code incorporates several newly developed techniques in SPH-needed multiphase compressible turbulent flow.