Plant quality and multiplication ratios of hellebores (Helleborus spp.) in vitro were observed with sucrose (1-3%), phosphate (1.25-6.25 mM), nitrate (39.8-69.8 mM), ammonium (5-35 mM), plant density, micronutrient dilution (from Woody Plant Medium), and thidiazuron (1-9 μM) as treatment factors. Treatment combinations were chosen using D-optimal criteria and tested in liquid media for two hybrid hellebore genotypes (Helleborus × nigercors and Helleborus × ballardiae ‘Raulston Remembered’). Analysis of variance indicated that sucrose, nitrate, and the sucrose × phosphate interaction had the largest positive effects on plant multiplication in liquid media. Multiplication was highest at maximum concentrations of phosphate and sucrose, indicating that ideal concentrations may be greater than the range tested. A 3 × 3 factorial study extending the range of sucrose and phosphate levels was conducted in gelled media. Optimal phosphate concentration for multiplication was 7.25 mM and optimal sucrose levels were 3% or less. The D-optimal response surface approach was successful for defining factors of interest to improve micropropagation of these hellebore hybtids. Plant nutrition appeared to be more important than the concentration of growth regulator present in the culture medium.