The influence of photosynthetic photon flux density (PPFD) and gibberellic acid (GA3) sprays on shoot elongation was determined for `Coral Bells' (Kurume or R. obstusum hybrid), `Fashion' (Glen Dale or R. indicum × Kurume hybrid), `Hexe' (R. obtusum × R. simsii hybrid), `Hinocrimson' (Kurume or R. obtusum hybrid), `Hinodegiri' (Kurume or R. obtusum hybrid), and `Red Wing' (Brooks hybrid) azalea. GA3 at 1 mm was more effective in stimulating shoot elongation of `Coral Bells', `Fashion', `Hinodegiri', and `Red Wing' than of `Hexe' or `Hinocrimson'. GA3 sprays were more effective in stimulating elongation when applied to plants growing at irradiance levels of 350 μmol·s-1·m-2 than to plants growing at either 200 or 100 μmol·s-1·-2. Gross photosynthesis of leaf segments was higher for a slow-growing cultivar (Hinocrimson) than for a faster-growing cultivar (Fashion). `Hinocrimson' produced stouter shoots (greater dry weight/cm) than did `Fashion'.